TODO (suggested by Nikolai)
1. Build query plan fro current query (inside storage::read) up to WithMergableState
2. Check, that plan is simple enough: Aggregating - Expression - Filter - ReadFromStorage (or simplier)
3. Check, that filter is the same as filter in projection, and also expression calculates the same aggregation keys as in projection
4. Return WithMergableState if projection applies
3 will be easier to do with ActionsDAG, cause it sees all functions, and dependencies are direct (but it is possible with ExpressionActions also)
Also need to figure out how prewhere works for projections, and
row_filter_policies.
wip
with the explicit data loading and verification.
If the function fails, the exception will re-throw upper,
cancelling the fetch in the handling of the replicated log entry,
but this event will also wake the PartCheckThread, which will
issue a re-fetch.
When the part data (e.g. data.bin) is corrupted, but the checksums.txt
is present -- explicitly deleting the checksums.txt.
Removed the extra logging, changes some exceptions message.
Now, instead of iterating through the directories, we iterate though
directories of on of the table disks (which doesn't give us a
substantial boost but is a bit neater to read).
- Updated the system.replication_queue command types.
- Fixed the part ptr being empty (added the checksum loading and
initialization).
- Removed extra logging.
- Updated the docs to make everything clear.
- Multiple small logger fixes.
- Changed the attach_part command -- now it's after check for the
covering parts -- motivation is to do less work with the checksums
fetching.
- Better logging in the integration test.
Found with fuzzer [1] for 00992_system_parts_race_condition_zookeeper:
2021.03.13 11:12:30.385188 [ 42042 ] {2d3a8e17-26be-47c1-974f-bd2c9fc7c3af} <Debug> executeQuery: (from [::1]:58192, using production parser) (comment: '/usr/share/clickhouse-test/queries/1_stateful/00153_aggregate_arena_race.sql') CREATE TABLE alter_tabl
e (a UInt8, b Int16, c Float32, d String, e Array(UInt8), f Nullable(UUID), g Tuple(UInt8, UInt16)) ENGINE = ReplicatedMergeTree('/clickhouse/tables/test_3.alter_table', 'r1') ORDER BY a PARTITION BY b % 10 SETTINGS old_parts_lifetime = 1, cleanup_delay_p
eriod = 1, cleanup_delay_period_random_add = 0;
...
2021.03.13 11:12:30.678387 [ 42042 ] {528cafc5-a02b-4df8-a531-a9a98e37b478} <Debug> executeQuery: (from [::1]:58192, using production parser) (comment: '/usr/share/clickhouse-test/queries/1_stateful/00153_aggregate_arena_race.sql') CREATE TABLE alter_table2 (a UInt8, b Int16, c Float32, d String, e Array(UInt8), f Nullable(UUID), g Tuple(UInt8, UInt16)) ENGINE = ReplicatedMergeTree('/clickhouse/tables/test_3.alter_table', 'r2') ORDER BY a PARTITION BY b % 10 SETTINGS old_parts_lifetime = 1, cleanup_delay_period = 1, cleanup_delay_period_random_add = 0;
...
2021.03.13 11:12:40.671994 [ 4193 ] {d96ee93c-69b0-4e89-b411-16c382ae27a8} <Debug> executeQuery: (from [::1]:59714, using production parser) (comment: '/usr/share/clickhouse-test/queries/1_stateful/00153_aggregate_arena_race.sql') OPTIMIZE TABLE alter_table FINAL
...
2021.03.13 11:12:40.990174 [ 2298 ] {a80f9306-3a73-4778-a921-db53249247e3} <Debug> executeQuery: (from [::1]:59768, using production parser) (comment: '/usr/share/clickhouse-test/queries/1_stateful/00153_aggregate_arena_race.sql') DROP TABLE alter_table;
...
2021.03.13 11:12:41.333054 [ 2298 ] {a80f9306-3a73-4778-a921-db53249247e3} <Debug> test_3.alter_table (d4fedaca-e0f6-4c22-9a4f-9f4d11b6b705): Removing part from filesystem 7_0_0_0
...
2021.03.13 11:12:41.335380 [ 2298 ] {a80f9306-3a73-4778-a921-db53249247e3} <Debug> DatabaseCatalog: Waiting for table d4fedaca-e0f6-4c22-9a4f-9f4d11b6b705 to be finally dropped
...
2021.03.13 11:12:41.781032 [ 4193 ] {d96ee93c-69b0-4e89-b411-16c382ae27a8} <Debug> test_3.alter_table (d4fedaca-e0f6-4c22-9a4f-9f4d11b6b705): Waiting for queue-0000000085 to disappear from r2 queue
...
2021.03.13 11:12:41.900039 [ 371 ] {} <Trace> test_3.alter_table2 (ReplicatedMergeTreeQueue): Not executing log entry queue-0000000085 of type MERGE_PARTS for part 7_0_0_1 because part 7_0_0_0 is not ready yet (log entry for that part is being processed).
2021.03.13 11:12:41.900213 [ 365 ] {} <Trace> test_3.alter_table2 (ReplicatedMergeTreeQueue): Cannot execute alter metadata queue-0000000056 with version 22 because another alter 21 must be executed before
2021.03.13 11:12:41.900231 [ 13762 ] {} <Trace> test_3.alter_table2 (ae877c49-0d30-416d-9afe-27fd457d8fc4): Executing log entry to merge parts -7_0_0_0 to -7_0_0_1
2021.03.13 11:12:41.900330 [ 13762 ] {} <Debug> test_3.alter_table2 (ae877c49-0d30-416d-9afe-27fd457d8fc4): Don't have all parts for merge -7_0_0_1; will try to fetch it instead
...
[1]: https://clickhouse-test-reports.s3.yandex.net/21691/eb3710c164b991b8d4f86b1435a65f9eceb8f1f5/stress_test_(address).html#fail1
The Year 1925 is a starting point because most of the timezones
switched to saner (mostly 15-minutes based) offsets somewhere
during 1924 or before. And that significantly simplifies implementation.
2238 is to simplify arithmetics for sanitizing LUT index access;
there are less than 0x1ffff days from 1925.
* Extended DateLUTImpl internal LUT to 0x1ffff items, some of which
represent negative (pre-1970) time values.
As a collateral benefit, Date now correctly supports dates up to 2149
(instead of 2106).
* Added a new strong typedef ExtendedDayNum, which represents dates
pre-1970 and post 2149.
* Functions that used to return DayNum now return ExtendedDayNum.
* Refactored DateLUTImpl to untie DayNum from the dual role of being
a value and an index (due to negative time). Index is now a different
type LUTIndex with explicit conversion functions from DatNum, time_t,
and ExtendedDayNum.
* Updated DateLUTImpl to properly support values close to epoch start
(1970-01-01 00:00), including negative ones.
* Reduced resolution of DateLUTImpl::Values::time_at_offset_change
to multiple of 15-minutes to allow storing 64-bits of time_t in
DateLUTImpl::Value while keeping same size.
* Minor performance updates to DateLUTImpl when building month LUT
by skipping non-start-of-month days.
* Fixed extractTimeZoneFromFunctionArguments to work correctly
with DateTime64.
* New unit-tests and stateless integration tests for both DateTime
and DateTime64.
ATTACH_PART into the replicated log.
The LogEntry now also has the pre-calculated part checksum for this
entry type, which is later used while searching in the detached/ folder
The original ticket idea was to search for the possibly available data
into the /detached folders for the GET_PART command, but
@tavplubix pointed out this would be quite expensive for an every
fetch.
So a new command is going to be introduced, ATTACH_PART, which will
cover ALTER TABLE ATTACH PART and only for which the search will start.
