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ClickHouse release 1.1.54370, 2018-03-16
New features:
- Added the
system.macros
table and auto updating of macros when the config file is changed. - Added the
SYSTEM RELOAD CONFIG
query. - Added the
maxIntersections(left_col, right_col)
aggregate function, which returns the maximum number of simultaneously intersecting intervals[left; right]
. ThemaxIntersectionsPosition(left, right)
function returns the beginning of the "maximum" interval. (Michael Furmur).
Improvements:
- When inserting data in a
Replicated
table, fewer requests are made toZooKeeper
(and most of the user-level errors have disappeared from theZooKeeper
log). - Added the ability to create aliases for sets. Example:
WITH (1, 2, 3) AS set SELECT number IN set FROM system.numbers LIMIT 10
.
Bug fixes:
- Fixed the
Illegal PREWHERE
error when reading fromMerge
tables overDistributed
tables. - Added fixes that allow you to run
clickhouse-server
in IPv4-only Docker containers. - Fixed a race condition when reading from system
system.parts_columns
tables. - Removed double buffering during a synchronous insert to a
Distributed
table, which could have caused the connection to timeout. - Fixed a bug that caused excessively long waits for an unavailable replica before beginning a
SELECT
query. - Fixed incorrect dates in the
system.parts
table. - Fixed a bug that made it impossible to insert data in a
Replicated
table ifchroot
was non-empty in the configuration of theZooKeeper
cluster. - Fixed the vertical merging algorithm for an empty
ORDER BY
table. - Restored the ability to use dictionaries in queries to remote tables, even if these dictionaries are not present on the requestor server. This functionality was lost in release 1.1.54362.
- Restored the behavior for queries like
SELECT * FROM remote('server2', default.table) WHERE col IN (SELECT col2 FROM default.table)
when the right side argument of theIN
should use a remotedefault.table
instead of a local one. This behavior was broken in version 1.1.54358. - Removed extraneous error-level logging of
Not found column ... in block
.
ClickHouse release 1.1.54356, 2018-03-06
New features:
- Aggregation without
GROUP BY
for an empty set (such asSELECT count(*) FROM table WHERE 0
) now returns a result with one row with null values for aggregate functions, in compliance with the SQL standard. To restore the old behavior (return an empty result), setempty_result_for_aggregation_by_empty_set
to 1. - Added type conversion for
UNION ALL
. Different alias names are allowed inSELECT
positions inUNION ALL
, in compliance with the SQL standard. - Arbitrary expressions are supported in
LIMIT BY
sections. Previously, it was only possible to use columns resulting fromSELECT
. - An index of
MergeTree
tables is used whenIN
is applied to a tuple of expressions from the columns of the primary key. Example:WHERE (UserID, EventDate) IN ((123, '2000-01-01'), ...)
(Anastasiya Tsarkova). - Added the
clickhouse-copier
tool for copying between clusters and resharding data (beta). - Added consistent hashing functions:
yandexConsistentHash
,jumpConsistentHash
,sumburConsistentHash
. They can be used as a sharding key in order to reduce the amount of network traffic during subsequent reshardings. - Added functions:
arrayAny
,arrayAll
,hasAny
,hasAll
,arrayIntersect
,arrayResize
. - Added the
arrayCumSum
function (Javi Santana). - Added the
parseDateTimeBestEffort
,parseDateTimeBestEffortOrZero
, andparseDateTimeBestEffortOrNull
functions to read the DateTime from a string containing text in a wide variety of possible formats. - It is now possible to change the logging settings without restarting the server.
- Added the
cluster
table function. Example:cluster(cluster_name, db, table)
. Theremote
table function can accept the cluster name as the first argument, if it is specified as an identifier. - Added the
create_table_query
andengine_full
virtual columns to thesystem.tables
table . Themetadata_modification_time
column is virtual. - Added the
data_path
andmetadata_path
columns tosystem.tables
andsystem.databases
tables, and added thepath
column to thesystem.parts
andsystem.parts_columns
tables. - Added additional information about merges in the
system.part_log
table. - An arbitrary partitioning key can be used for the
system.query_log
table (Kirill Shvakov). - The
SHOW TABLES
query now also shows temporary tables. Added temporary tables and theis_temporary
column tosystem.tables
(zhang2014). - Added the
DROP TEMPORARY TABLE
query (zhang2014). - Support for
SHOW CREATE TABLE
for temporary tables (zhang2014). - Added the
system_profile
configuration parameter for the settings used by internal processes. - Support for loading
object_id
as an attribute inMongoDB
dictionaries (Pavel Litvinenko). - Reading
null
as the default value when loading data for an external dictionary with theMongoDB
source (Pavel Litvinenko). - Reading
DateTime
values in theValues
format from a Unix timestamp without single quotes. - Failover is supported in
remote
table functions for cases when some of the replicas are missing the requested table. - Configuration settings can be overridden in the command line when you run
clickhouse-server
. Example:clickhouse-server -- --logger.level=information
. - Implemented the
empty
function from aFixedString
argument: the function returns 1 if the string consists entirely of null bytes (zhang2014). - Added the
listen_try
configuration parameter for listening to at least one of the listen addresses without quitting, if some of the addresses can't be listened to (useful for systems with disabled support for IPv4 or IPv6). - Added the
VersionedCollapsingMergeTree
table engine. - Support for rows and arbitrary numeric types for the
library
dictionary source. MergeTree
tables can be used without a primary key (you need to specifyORDER BY tuple()
).- A
Nullable
type can beCAST
to a non-Nullable
type if the argument is notNULL
. RENAME TABLE
can be performed forVIEW
.- Added the
odbc_default_field_size
option, which allows you to extend the maximum size of the value loaded from an ODBC source (by default, it is 1024).
Improvements:
- Limits and quotas on the result are no longer applied to intermediate data for
INSERT SELECT
queries or forSELECT
subqueries. - Fewer false triggers of
force_restore_data
when checking the status ofReplicated
tables when the server starts. - Added the
allow_distributed_ddl
option. - Nondeterministic functions are not allowed in expressions for
MergeTree
table keys. - Files with substitutions from
config.d
directories are loaded in alphabetical order. - Improved performance of the
arrayElement
function in the case of a constant multidimensional array with an empty array as one of the elements. Example:[[1], []][x]
. - The server starts faster now when using configuration files with very large substitutions (for instance, very large lists of IP networks).
- When running a query, table valued functions run once. Previously,
remote
andmysql
table valued functions performed the same query twice to retrieve the table structure from a remote server. - The
MkDocs
documentation generator is used. - When you try to delete a table column that
DEFAULT
/MATERIALIZED
expressions of other columns depend on, an exception is thrown (zhang2014). - Added the ability to parse an empty line in text formats as the number 0 for
Float
data types. This feature was previously available but was lost in release 1.1.54342. Enum
values can be used inmin
,max
,sum
and some other functions. In these cases, it uses the corresponding numeric values. This feature was previously available but was lost in the release 1.1.54337.- Added
max_expanded_ast_elements
to restrict the size of the AST after recursively expanding aliases.
Bug fixes:
- Fixed cases when unnecessary columns were removed from subqueries in error, or not removed from subqueries containing
UNION ALL
. - Fixed a bug in merges for
ReplacingMergeTree
tables. - Fixed synchronous insertions in
Distributed
tables (insert_distributed_sync = 1
). - Fixed segfault for certain uses of
FULL
andRIGHT JOIN
with duplicate columns in subqueries. - Fixed the order of the
source
andlast_exception
columns in thesystem.dictionaries
table. - Fixed a bug when the
DROP DATABASE
query did not delete the file with metadata. - Fixed the
DROP DATABASE
query forDictionary
databases. - Fixed the low precision of
uniqHLL12
anduniqCombined
functions for cardinalities greater than 100 million items (Alex Bocharov). - Fixed the calculation of implicit default values when necessary to simultaneously calculate default explicit expressions in
INSERT
queries (zhang2014). - Fixed a rare case when a query to a
MergeTree
table couldn't finish (chenxing-xc). - Fixed a crash that occurred when running a
CHECK
query forDistributed
tables if all shards are local (chenxing.xc). - Fixed a slight performance regression with functions that use regular expressions.
- Fixed a performance regression when creating multidimensional arrays from complex expressions.
- Fixed a bug that could cause an extra
FORMAT
section to appear in an.sql
file with metadata. - Fixed a bug that caused the
max_table_size_to_drop
limit to apply when trying to delete aMATERIALIZED VIEW
looking at an explicitly specified table. - Fixed incompatibility with old clients (old clients were sometimes sent data with the
DateTime('timezone')
type, which they do not understand). - Fixed a bug when reading
Nested
column elements of structures that were added usingALTER
but that are empty for the old partitions, when the conditions for these columns moved toPREWHERE
. - Fixed a bug when filtering tables by virtual
_table
columns in queries toMerge
tables. - Fixed a bug when using
ALIAS
columns inDistributed
tables. - Fixed a bug that made dynamic compilation impossible for queries with aggregate functions from the
quantile
family. - Fixed a race condition in the query execution pipeline that occurred in very rare cases when using
Merge
tables with a large number of tables, and when usingGLOBAL
subqueries. - Fixed a crash when passing arrays of different sizes to an
arrayReduce
function when using aggregate functions from multiple arguments. - Prohibited the use of queries with
UNION ALL
in aMATERIALIZED VIEW
.
Backward incompatible changes:
- Removed the
distributed_ddl_allow_replicated_alter
option. This behavior is enabled by default. - Removed the
UnsortedMergeTree
engine.
ClickHouse release 1.1.54343, 2018-02-05
- Added macros support for defining cluster names in distributed DDL queries and constructors of Distributed tables:
CREATE TABLE distr ON CLUSTER '{cluster}' (...) ENGINE = Distributed('{cluster}', 'db', 'table')
. - Now the table index is used for conditions like
expr IN (subquery)
. - Improved processing of duplicates when inserting to Replicated tables, so they no longer slow down execution of the replication queue.
ClickHouse release 1.1.54342, 2018-01-22
This release contains bug fixes for the previous release 1.1.54337:
- Fixed a regression in 1.1.54337: if the default user has readonly access, then the server refuses to start up with the message
Cannot create database in readonly mode
. - Fixed a regression in 1.1.54337: on systems with
systemd
, logs are always written to syslog regardless of the configuration; the watchdog script still usesinit.d
. - Fixed a regression in 1.1.54337: wrong default configuration in the Docker image.
- Fixed nondeterministic behaviour of GraphiteMergeTree (you can notice it in log messages
Data after merge is not byte-identical to data on another replicas
). - Fixed a bug that may lead to inconsistent merges after OPTIMIZE query to Replicated tables (you may notice it in log messages
Part ... intersects previous part
). - Buffer tables now work correctly when MATERIALIZED columns are present in the destination table (by zhang2014).
- Fixed a bug in implementation of NULL.
ClickHouse release 1.1.54337, 2018-01-18
New features:
- Added support for storage of multidimensional arrays and tuples (
Tuple
data type) in tables. - Added support for table functions in
DESCRIBE
andINSERT
queries. Added support for subqueries inDESCRIBE
. Examples:DESC TABLE remote('host', default.hits)
;DESC TABLE (SELECT 1)
;INSERT INTO TABLE FUNCTION remote('host', default.hits)
. Support forINSERT INTO TABLE
syntax in addition toINSERT INTO
. - Improved support for timezones. The
DateTime
data type can be annotated with the timezone that is used for parsing and formatting in text formats. Example:DateTime('Europe/Moscow')
. When timezones are specified in functions for DateTime arguments, the return type will track the timezone, and the value will be displayed as expected. - Added the functions
toTimeZone
,timeDiff
,toQuarter
,toRelativeQuarterNum
. ThetoRelativeHour
/Minute
/Second
functions can take a value of typeDate
as an argument. The name of thenow
function has been made case-insensitive. - Added the
toStartOfFifteenMinutes
function (Kirill Shvakov). - Added the
clickhouse format
tool for formatting queries. - Added the
format_schema_path
configuration parameter (Marek Vavruša). It is used for specifying a schema inCap'n'Proto
format. Schema files can be located only in the specified directory. - Added support for config substitutions (
incl
andconf.d
) for configuration of external dictionaries and models (Pavel Yakunin). - Added a column with documentation for the
system.settings
table (Kirill Shvakov). - Added the
system.parts_columns
table with information about column sizes in each data part ofMergeTree
tables. - Added the
system.models
table with information about loadedCatBoost
machine learning models. - Added the
mysql
andodbc
table functions along with the correspondingMySQL
andODBC
table engines for working with foreign databases. This feature is in the beta stage. - Added the possibility to pass an argument of type
AggregateFunction
for thegroupArray
aggregate function (so you can create an array of states of some aggregate function). - Removed restrictions on various combinations of aggregate function combinators. For example, you can use
avgForEachIf
as well asavgIfForEach
aggregate functions, which have different behaviors. - The
-ForEach
aggregate function combinator is extended for the case of aggregate functions of multiple arguments. - Added support for aggregate functions of
Nullable
arguments even for cases when the function returns a non-Nullable
result (added with the contribution of Silviu Caragea). Examples:groupArray
,groupUniqArray
,topK
. - Added the
max_client_network_bandwidth
command line parameter forclickhouse-client
(Kirill Shvakov). - Users with the
readonly = 2
setting are allowed to work with TEMPORARY tables (CREATE, DROP, INSERT...) (Kirill Shvakov). - Added support for using multiple consumers with the
Kafka
engine. Extended configuration options forKafka
(Marek Vavruša). - Added the
intExp2
andintExp10
functions. - Added the
sumKahan
aggregate function (computationally stable summation of floating point numbers). - Added toNumberOrNull functions, where Number is a numeric type.
- Added support for the
WITH
clause for anINSERT SELECT
query (by zhang2014). - Added the settings
http_connection_timeout
,http_send_timeout
, andhttp_receive_timeout
. In particular, these settings are used for downloading data parts for replication. Changing these settings allows for faster failover if the network is overloaded. - Added support for the
ALTER
query for tables of typeNull
(Anastasiya Tsarkova). Tables of typeNull
are often used with materialized views. - The
reinterpretAsString
function is extended for all data types that are stored contiguously in memory. - Added the
--silent
option for theclickhouse-local
tool. It suppresses printing query execution info in stderr. - Added support for reading values of type
Date
from text in a format where the month and/or day of the month is specified using a single digit instead of two digits (Amos Bird).
Performance optimizations:
- Improved performance of
min
,max
,any
,anyLast
,anyHeavy
,argMin
,argMax
aggregate functions for String arguments. - Improved performance of
isInfinite
,isFinite
,isNaN
,roundToExp2
functions. - Improved performance of parsing and formatting values of type
Date
andDateTime
in text formats. - Improved performance and precision of parsing floating point numbers.
- Lowered memory usage for
JOIN
in the case when the left and right parts have columns with identical names that are not contained inUSING
. - Improved performance of
varSamp
,varPop
,stddevSamp
,stddevPop
,covarSamp
,covarPop
, andcorr
aggregate functions by reducing computational stability. The old functions are available under the names:varSampStable
,varPopStable
,stddevSampStable
,stddevPopStable
,covarSampStable
,covarPopStable
,corrStable
.
Bug fixes:
- Fixed data deduplication after running a
DROP PARTITION
query. In the previous version, dropping a partition and INSERTing the same data again was not working because INSERTed blocks were considered duplicates. - Fixed a bug that could lead to incorrect interpretation of the
WHERE
clause forCREATE MATERIALIZED VIEW
queries withPOPULATE
. - Fixed a bug in using the
root_path
parameter in thezookeeper_servers
configuration. - Fixed unexpected results of passing the
Date
argument totoStartOfDay
. - Fixed the
addMonths
andsubtractMonths
functions and the arithmetic forINTERVAL n MONTH
in cases when the result has the previous year. - Added missing support for the
UUID
data type forDISTINCT
,JOIN
, anduniq
aggregate functions and external dictionaries (Evgeniy Ivanov). Support forUUID
is still incomplete. - Fixed
SummingMergeTree
behavior in cases when the rows summed to zero. - Various fixes for the
Kafka
engine (Marek Vavruša). - Fixed incorrect behavior of the
Join
table engine (Amos Bird). - Fixed incorrect allocator behavior under FreeBSD and OS X.
- The
extractAll
function now supports empty matches. - Fixed an error that blocked usage of
libressl
instead ofopenssl
. - Fixed the
CREATE TABLE AS SELECT
query from temporary tables. - Fixed non-atomicity of updating the replication queue. This could lead to replicas being out of sync until the server restarts.
- Fixed possible overflow in
gcd
,lcm
andmodulo
(%
operator) (Maks Skorokhod). -preprocessed
files are now created after changingumask
(umask
can be changed in the config).- Fixed a bug in the background check of parts (
MergeTreePartChecker
) when using a custom partition key. - Fixed parsing of tuples (values of the
Tuple
data type) in text formats. - Improved error messages about incompatible types passed to
multiIf
,array
and some other functions. - Support for
Nullable
types is completely reworked. Fixed bugs that may lead to a server crash. Fixed almost all other bugs related to NULL support: incorrect type conversions in INSERT SELECT, insufficient support for Nullable in HAVING and PREWHERE,join_use_nulls
mode, Nullable types as arguments of OR operator, etc. - Fixed various bugs related to internal semantics of data types. Examples: unnecessary summing of
Enum
type fields inSummingMergeTree
; alignment ofEnum
types in Pretty formats, etc. - Stricter checks for allowed combinations of composite columns. Fixed several bugs that could lead to a server crash.
- Fixed the overflow when specifying a very large parameter for the
FixedString
data type. - Fixed a bug in the
topK
aggregate function in a generic case. - Added the missing check for equality of array sizes in arguments of n-ary variants of aggregate functions with an
-Array
combinator. - Fixed the
--pager
option forclickhouse-client
(by ks1322). - Fixed the precision of the
exp10
function. - Fixed the behavior of the
visitParamExtract
function for better compliance with documentation. - Fixed the crash when incorrect data types are specified.
- Fixed the behavior of
DISTINCT
in the case when all columns are constants. - Fixed query formatting in the case of using the
tupleElement
function with a complex constant expression as the tuple element index. - Fixed the
Dictionary
table engine for dictionaries of typerange_hashed
. - Fixed a bug that leads to excessive rows in the result of
FULL
andRIGHT JOIN
(Amos Bird). - Fixed a server crash when creating and removing temporary files in
config.d
directories during config reload. - Fixed the
SYSTEM DROP DNS CACHE
query: the cache was flushed but addresses of cluster nodes were not updated. - Fixed the behavior of
MATERIALIZED VIEW
after executingDETACH TABLE
for the table under the view (Marek Vavruša).
Build improvements:
- Builds use
pbuilder
. The build process is almost completely independent of the build host environment. - A single build is used for different OS versions. Packages and binaries have been made compatible with a wide range of Linux systems.
- Added the
clickhouse-test
package. It can be used to run functional tests. - The source tarball can now be published to the repository. It can be used to reproduce the build without using GitHub.
- Added limited integration with Travis CI. Due to limits on build time in Travis, only the debug build is tested and a limited subset of tests are run.
- Added support for
Cap'n'Proto
in the default build. - Changed the format of documentation sources from
Restructured Text
toMarkdown
. - Added support for
systemd
(Vladimir Smirnov). It is disabled by default due to incompatibility with some OS images and can be enabled manually. - For dynamic code generation,
clang
andlld
are embedded into theclickhouse
binary. They can also be invoked asclickhouse clang
andclickhouse lld
. - Removed usage of GNU extensions from the code. Enabled the
-Wextra
option. When building withclang
,libc++
is used instead oflibstdc++
. - Extracted
clickhouse_parsers
andclickhouse_common_io
libraries to speed up builds of various tools.
Backward incompatible changes:
- The format for marks in
Log
type tables that containNullable
columns was changed in a backward incompatible way. If you have these tables, you should convert them to theTinyLog
type before starting up the new server version. To do this, replaceENGINE = Log
withENGINE = TinyLog
in the corresponding.sql
file in themetadata
directory. If your table doesn't haveNullable
columns or if the type of your table is notLog
, then you don't need to do anything. - Removed the
experimental_allow_extended_storage_definition_syntax
setting. Now this feature is enabled by default. - To avoid confusion, the
runningIncome
function has been renamed torunningDifferenceStartingWithFirstValue
. - Removed the
FROM ARRAY JOIN arr
syntax when ARRAY JOIN is specified directly after FROM with no table (Amos Bird). - Removed the
BlockTabSeparated
format that was used solely for demonstration purposes. - Changed the serialization format of intermediate states of the aggregate functions
varSamp
,varPop
,stddevSamp
,stddevPop
,covarSamp
,covarPop
, andcorr
. If you have stored states of these aggregate functions in tables (using the AggregateFunction data type or materialized views with corresponding states), please write to clickhouse-feedback@yandex-team.com. - In previous server versions there was an undocumented feature: if an aggregate function depends on parameters, you can still specify it without parameters in the AggregateFunction data type. Example:
AggregateFunction(quantiles, UInt64)
instead ofAggregateFunction(quantiles(0.5, 0.9), UInt64)
. This feature was lost. Although it was undocumented, we plan to support it again in future releases. - Enum data types cannot be used in min/max aggregate functions. The possibility will be returned back in future release.
Please note when upgrading:
- When doing a rolling update on a cluster, at the point when some of the replicas are running the old version of ClickHouse and some are running the new version, replication is temporarily stopped and the message
unknown parameter 'shard'
appears in the log. Replication will continue after all replicas of the cluster are updated. - If you have different ClickHouse versions on the cluster, you can get incorrect results for distributed queries with the aggregate functions
varSamp
,varPop
,stddevSamp
,stddevPop
,covarSamp
,covarPop
, andcorr
. You should update all cluster nodes.
ClickHouse release 1.1.54327, 2017-12-21
This release contains bug fixes for the previous release 1.1.54318:
- Fixed bug with possible race condition in replication that could lead to data loss. This issue affects versions 1.1.54310 and 1.1.54318. If you use one of these versions with Replicated tables, the update is strongly recommended. This issue shows in logs in Warning messages like
Part ... from own log doesn't exist.
The issue is relevant even if you don't see these messages in logs.
ClickHouse release 1.1.54318, 2017-11-30
This release contains bug fixes for the previous release 1.1.54310:
- Fixed incorrect row deletions during merges in the SummingMergeTree engine
- Fixed a memory leak in unreplicated MergeTree engines
- Fixed performance degradation with frequent inserts in MergeTree engines
- Fixed an issue that was causing the replication queue to stop running
- Fixed rotation and archiving of server logs
ClickHouse release 1.1.54310, 2017-11-01
New features:
- Custom partitioning key for the MergeTree family of table engines.
- Kafka table engine.
- Added support for loading CatBoost models and applying them to data stored in ClickHouse.
- Added support for time zones with non-integer offsets from UTC.
- Added support for arithmetic operations with time intervals.
- The range of values for the Date and DateTime types is extended to the year 2105.
- Added the
CREATE MATERIALIZED VIEW x TO y
query (specifies an existing table for storing the data of a materialized view). - Added the
ATTACH TABLE
query without arguments. - The processing logic for Nested columns with names ending in -Map in a SummingMergeTree table was extracted to the sumMap aggregate function. You can now specify such columns explicitly.
- Max size of the IP trie dictionary is increased to 128M entries.
- Added the
getSizeOfEnumType
function. - Added the
sumWithOverflow
aggregate function. - Added support for the Cap'n Proto input format.
- You can now customize compression level when using the zstd algorithm.
Backward incompatible changes:
- Creation of temporary tables with an engine other than Memory is forbidden.
- Explicit creation of tables with the View or MaterializedView engine is forbidden.
- During table creation, a new check verifies that the sampling key expression is included in the primary key.
Bug fixes:
- Fixed hangups when synchronously inserting into a Distributed table.
- Fixed nonatomic adding and removing of parts in Replicated tables.
- Data inserted into a materialized view is not subjected to unnecessary deduplication.
- Executing a query to a Distributed table for which the local replica is lagging and remote replicas are unavailable does not result in an error anymore.
- Users don't need access permissions to the
default
database to create temporary tables anymore. - Fixed crashing when specifying the Array type without arguments.
- Fixed hangups when the disk volume containing server logs is full.
- Fixed an overflow in the
toRelativeWeekNum
function for the first week of the Unix epoch.
Build improvements:
- Several third-party libraries (notably Poco) were updated and converted to git submodules.
ClickHouse release 1.1.54304, 2017-10-19
New features:
- TLS support in the native protocol (to enable, set
tcp_ssl_port
inconfig.xml
)
Bug fixes:
ALTER
for replicated tables now tries to start running as soon as possible- Fixed crashing when reading data with the setting
preferred_block_size_bytes=0
- Fixed crashes of
clickhouse-client
whenPage Down
is pressed - Correct interpretation of certain complex queries with
GLOBAL IN
andUNION ALL
FREEZE PARTITION
always works atomically now- Empty POST requests now return a response with code 411
- Fixed interpretation errors for expressions like
CAST(1 AS Nullable(UInt8))
- Fixed an error when reading columns like
Array(Nullable(String))
fromMergeTree
tables - Fixed crashing when parsing queries like
SELECT dummy AS dummy, dummy AS b
- Users are updated correctly when
users.xml
is invalid - Correct handling when an executable dictionary returns a non-zero response code
ClickHouse release 1.1.54292, 2017-09-20
New features:
- Added the
pointInPolygon
function for working with coordinates on a coordinate plane. - Added the
sumMap
aggregate function for calculating the sum of arrays, similar toSummingMergeTree
. - Added the
trunc
function. Improved performance of the rounding functions (round
,floor
,ceil
,roundToExp2
) and corrected the logic of how they work. Changed the logic of theroundToExp2
function for fractions and negative numbers. - The ClickHouse executable file is now less dependent on the libc version. The same ClickHouse executable file can run on a wide variety of Linux systems. Note: There is still a dependency when using compiled queries (with the setting
compile = 1
, which is not used by default). - Reduced the time needed for dynamic compilation of queries.
Bug fixes:
- Fixed an error that sometimes produced
part ... intersects previous part
messages and weakened replica consistency. - Fixed an error that caused the server to lock up if ZooKeeper was unavailable during shutdown.
- Removed excessive logging when restoring replicas.
- Fixed an error in the UNION ALL implementation.
- Fixed an error in the concat function that occurred if the first column in a block has the Array type.
- Progress is now displayed correctly in the system.merges table.
ClickHouse release 1.1.54289, 2017-09-13
New features:
SYSTEM
queries for server administration:SYSTEM RELOAD DICTIONARY
,SYSTEM RELOAD DICTIONARIES
,SYSTEM DROP DNS CACHE
,SYSTEM SHUTDOWN
,SYSTEM KILL
.- Added functions for working with arrays:
concat
,arraySlice
,arrayPushBack
,arrayPushFront
,arrayPopBack
,arrayPopFront
. - Added the
root
andidentity
parameters for the ZooKeeper configuration. This allows you to isolate individual users on the same ZooKeeper cluster. - Added the aggregate functions
groupBitAnd
,groupBitOr
, andgroupBitXor
(for compatibility, they can also be accessed with the namesBIT_AND
,BIT_OR
, andBIT_XOR
). - External dictionaries can be loaded from MySQL by specifying a socket in the filesystem.
- External dictionaries can be loaded from MySQL over SSL (the
ssl_cert
,ssl_key
, andssl_ca
parameters). - Added the
max_network_bandwidth_for_user
setting to restrict the overall bandwidth use for queries per user. - Support for
DROP TABLE
for temporary tables. - Support for reading
DateTime
values in Unix timestamp format from theCSV
andJSONEachRow
formats. - Lagging replicas in distributed queries are now excluded by default (the default threshold is 5 minutes).
- FIFO locking is used during ALTER: an ALTER query isn't blocked indefinitely for continuously running queries.
- Option to set
umask
in the config file. - Improved performance for queries with
DISTINCT
.
Bug fixes:
- Improved the process for deleting old nodes in ZooKeeper. Previously, old nodes sometimes didn't get deleted if there were very frequent inserts, which caused the server to be slow to shut down, among other things.
- Fixed randomization when choosing hosts for the connection to ZooKeeper.
- Fixed the exclusion of lagging replicas in distributed queries if the replica is localhost.
- Fixed an error where a data part in a
ReplicatedMergeTree
table could be broken after runningALTER MODIFY
on an element in aNested
structure. - Fixed an error that could cause SELECT queries to "hang".
- Improvements to distributed DDL queries.
- Fixed the query
CREATE TABLE ... AS <materialized view>
. - Resolved the deadlock in the
ALTER ... CLEAR COLUMN IN PARTITION
query forBuffer
tables. - Fixed the invalid default value for
Enum
s (0 instead of the minimum) when using theJSONEachRow
andTSKV
formats. - Resolved the appearance of zombie processes when using a dictionary with an
executable
source. - Fixed segfault for the HEAD query.
Improvements to development workflow and ClickHouse build:
- You can use
pbuilder
to build ClickHouse. - You can use
libc++
instead oflibstdc++
for builds on Linux. - Added instructions for using static code analysis tools:
Coverity
,clang-tidy
, andcppcheck
.
Please note when upgrading:
- There is now a higher default value for the MergeTree setting
max_bytes_to_merge_at_max_space_in_pool
(the maximum total size of data parts to merge, in bytes): it has increased from 100 GiB to 150 GiB. This might result in large merges running after the server upgrade, which could cause an increased load on the disk subsystem. If the free space available on the server is less than twice the total amount of the merges that are running, this will cause all other merges to stop running, including merges of small data parts. As a result, INSERT requests will fail with the message "Merges are processing significantly slower than inserts." Use theSELECT * FROM system.merges
request to monitor the situation. You can also check theDiskSpaceReservedForMerge
metric in thesystem.metrics
table, or in Graphite. You don't need to do anything to fix this, since the issue will resolve itself once the large merges finish. If you find this unacceptable, you can restore the previous value for themax_bytes_to_merge_at_max_space_in_pool
setting (to do this, go to the<merge_tree>
section in config.xml, set<max_bytes_to_merge_at_max_space_in_pool>107374182400</max_bytes_to_merge_at_max_space_in_pool>
and restart the server).
ClickHouse release 1.1.54284, 2017-08-29
- This is bugfix release for previous 1.1.54282 release. It fixes ZooKeeper nodes leak in
parts/
directory.
ClickHouse release 1.1.54282, 2017-08-23
This is a bugfix release. The following bugs were fixed:
DB::Exception: Assertion violation: !_path.empty()
error when inserting into a Distributed table.- Error when parsing inserted data in RowBinary format if the data begins with ';' character.
- Errors during runtime compilation of certain aggregate functions (e.g.
groupArray()
).
ClickHouse release 1.1.54276, 2017-08-16
New features:
- You can use an optional WITH clause in a SELECT query. Example query:
WITH 1+1 AS a SELECT a, a*a
- INSERT can be performed synchronously in a Distributed table: OK is returned only after all the data is saved on all the shards. This is activated by the setting insert_distributed_sync=1.
- Added the UUID data type for working with 16-byte identifiers.
- Added aliases of CHAR, FLOAT and other types for compatibility with the Tableau.
- Added the functions toYYYYMM, toYYYYMMDD, and toYYYYMMDDhhmmss for converting time into numbers.
- You can use IP addresses (together with the hostname) to identify servers for clustered DDL queries.
- Added support for non-constant arguments and negative offsets in the function
substring(str, pos, len).
- Added the max_size parameter for the
groupArray(max_size)(column)
aggregate function, and optimized its performance.
Major changes:
- Improved security: all server files are created with 0640 permissions (can be changed via config parameter).
- Improved error messages for queries with invalid syntax.
- Significantly reduced memory consumption and improved performance when merging large sections of MergeTree data.
- Significantly increased the performance of data merges for the ReplacingMergeTree engine.
- Improved performance for asynchronous inserts from a Distributed table by batching multiple source inserts. To enable this functionality, use the setting distributed_directory_monitor_batch_inserts=1.
Backward incompatible changes:
- Changed the binary format of aggregate states of
groupArray(array_column)
functions for arrays.
Complete list of changes:
- Added the
output_format_json_quote_denormals
setting, which enables outputting nan and inf values in JSON format. - Optimized thread allocation when reading from a Distributed table.
- Settings can be modified in readonly mode if the value doesn't change.
- Added the ability to read fractional granules of the MergeTree engine in order to meet restrictions on the block size specified in the preferred_block_size_bytes setting. The purpose is to reduce the consumption of RAM and increase cache locality when processing queries from tables with large columns.
- Efficient use of indexes that contain expressions like
toStartOfHour(x)
for conditions liketoStartOfHour(x) op сonstexpr.
- Added new settings for MergeTree engines (the merge_tree section in config.xml):
- replicated_deduplication_window_seconds sets the size of deduplication window in seconds for Replicated tables.
- cleanup_delay_period sets how often to start cleanup to remove outdated data.
- replicated_can_become_leader can prevent a replica from becoming the leader (and assigning merges).
- Accelerated cleanup to remove outdated data from ZooKeeper.
- Multiple improvements and fixes for clustered DDL queries. Of particular interest is the new setting distributed_ddl_task_timeout, which limits the time to wait for a response from the servers in the cluster.
- Improved display of stack traces in the server logs.
- Added the "none" value for the compression method.
- You can use multiple dictionaries_config sections in config.xml.
- It is possible to connect to MySQL through a socket in the file system.
- The
system.parts
table has a new column with information about the size of marks, in bytes.
Bug fixes:
- Distributed tables using a Merge table now work correctly for a SELECT query with a condition on the _table field.
- Fixed a rare race condition in ReplicatedMergeTree when checking data parts.
- Fixed possible freezing on "leader election" when starting a server.
- The max_replica_delay_for_distributed_queries setting was ignored when using a local replica of the data source. This has been fixed.
- Fixed incorrect behavior of
ALTER TABLE CLEAR COLUMN IN PARTITION
when attempting to clean a non-existing column. - Fixed an exception in the multiIf function when using empty arrays or strings.
- Fixed excessive memory allocations when deserializing Native format.
- Fixed incorrect auto-update of Trie dictionaries.
- Fixed an exception when running queries with a GROUP BY clause from a Merge table when using SAMPLE.
- Fixed a crash of GROUP BY when using distributed_aggregation_memory_efficient=1.
- Now you can specify the database.table in the right side of IN and JOIN.
- Too many threads were used for parallel aggregation. This has been fixed.
- Fixed how the "if" function works with FixedString arguments.
- SELECT worked incorrectly from a Distributed table for shards with a weight of 0. This has been fixed.
- Crashes no longer occur when running
CREATE VIEW IF EXISTS.
- Fixed incorrect behavior when input_format_skip_unknown_fields=1 is set and there are negative numbers.
- Fixed an infinite loop in the
dictGetHierarchy()
function if there is some invalid data in the dictionary. - Fixed
Syntax error: unexpected (...)
errors when running distributed queries with subqueries in an IN or JOIN clause and Merge tables. - Fixed the incorrect interpretation of a SELECT query from Dictionary tables.
- Fixed the "Cannot mremap" error when using arrays in IN and JOIN clauses with more than 2 billion elements.
- Fixed the failover for dictionaries with MySQL as the source.
Improved workflow for developing and assembling ClickHouse:
- Builds can be assembled in Arcadia.
- You can use gcc 7 to compile ClickHouse.
- Parallel builds using ccache+distcc are faster now.
ClickHouse release 1.1.54245, 2017-07-04
New features:
- Distributed DDL (for example,
CREATE TABLE ON CLUSTER
). - The replicated request
ALTER TABLE CLEAR COLUMN IN PARTITION.
- The engine for Dictionary tables (access to dictionary data in the form of a table).
- Dictionary database engine (this type of database automatically has Dictionary tables available for all the connected external dictionaries).
- You can check for updates to the dictionary by sending a request to the source.
- Qualified column names
- Quoting identifiers using double quotation marks.
- Sessions in the HTTP interface.
- The OPTIMIZE query for a Replicated table can can run not only on the leader.
Backward incompatible changes:
- Removed SET GLOBAL.
Minor changes:
- If an alert is triggered, the full stack trace is printed into the log.
- Relaxed the verification of the number of damaged or extra data parts at startup (there were too many false positives).
Bug fixes:
- Fixed a bad connection "sticking" when inserting into a Distributed table.
- GLOBAL IN now works for a query from a Merge table that looks at a Distributed table.
- The incorrect number of cores was detected on a Google Compute Engine virtual machine. This has been fixed.
- Changes in how an executable source of cached external dictionaries works.
- Fixed the comparison of strings containing null characters.
- Fixed the comparison of Float32 primary key fields with constants.
- Previously, an incorrect estimate of the size of a field could lead to overly large allocations. This has been fixed.
- Fixed a crash when querying a Nullable column added to a table using ALTER.
- Fixed a crash when sorting by a Nullable column, if the number of rows is less than LIMIT.
- Fixed an ORDER BY subquery consisting of only constant values.
- Previously, a Replicated table could remain in the invalid state after a failed DROP TABLE.
- Aliases for scalar subqueries with empty results are no longer lost.
- Now a query that used compilation does not fail with an error if the .so file gets damaged.