Add log_queries_min_type to filter which entries will be written to query_log

Can be used to write into query_log only failed queries (i.e. on memory
exceeded error), by using:

  set log_queries_min_type='EXCEPTION_WHILE_PROCESSING'

docs/en/operations/settings/settings.md

@@ -507,6 +507,24 @@ Example:
 log_queries=1
 ```
 
+## log\_queries\_min\_type {#settings-log-queries-min-type}
+
+`query_log` minimal type to log.
+
+Possible values:
+- `QUERY_START` (`=1`)
+- `QUERY_FINISH` (`=2`)
+- `EXCEPTION_BEFORE_START` (`=3`)
+- `EXCEPTION_WHILE_PROCESSING` (`=4`)
+
+Default value: `QUERY_START`.
+
+Can be used to limit which entiries will goes to `query_log`, say you are interesting only in errors, then you can use `EXCEPTION_WHILE_PROCESSING`:
+
+``` text
+log_queries_min_type='EXCEPTION_WHILE_PROCESSING'
+```
+
 ## log\_query\_threads {#settings-log-query-threads}
 
 Setting up query threads logging.

src/Core/Settings.h

@@ -149,7 +149,7 @@ struct Settings : public SettingsCollection<Settings>
     M(SettingInt64, os_thread_priority, 0, "If non zero - set corresponding 'nice' value for query processing threads. Can be used to adjust query priority for OS scheduler.", 0) \
     \
     M(SettingBool, log_queries, 0, "Log requests and write the log to the system table.", 0) \
-    \
+    M(SettingLogQueriesType, log_queries_min_type, QueryLogElementType::QUERY_START, "query_log minimal type to log, possible values (from low to high): QUERY_START, QUERY_FINISH, EXCEPTION_BEFORE_START, EXCEPTION_WHILE_PROCESSING.", 0) \
     M(SettingUInt64, log_queries_cut_to_length, 100000, "If query length is greater than specified threshold (in bytes), then cut query when writing to query log. Also limit length of printed query in ordinary text log.", 0) \
     \
     M(SettingDistributedProductMode, distributed_product_mode, DistributedProductMode::DENY, "How are distributed subqueries performed inside IN or JOIN sections?", IMPORTANT) \

src/Core/SettingsCollection.cpp

@@ -542,6 +542,13 @@ IMPLEMENT_SETTING_ENUM(FormatSettings::DateTimeInputFormat, DATE_TIME_INPUT_FORM
     M(trace, "trace")
 IMPLEMENT_SETTING_ENUM(LogsLevel, LOGS_LEVEL_LIST_OF_NAMES, ErrorCodes::BAD_ARGUMENTS)
 
+#define LOG_QUERIES_TYPE_LIST_OF_NAMES(M) \
+    M(QUERY_START, "QUERY_START") \
+    M(QUERY_FINISH, "QUERY_FINISH") \
+    M(EXCEPTION_BEFORE_START, "EXCEPTION_BEFORE_START") \
+    M(EXCEPTION_WHILE_PROCESSING, "EXCEPTION_WHILE_PROCESSING")
+IMPLEMENT_SETTING_ENUM(QueryLogElementType, LOG_QUERIES_TYPE_LIST_OF_NAMES, ErrorCodes::BAD_ARGUMENTS)
+
 
 namespace details
 {

src/Core/SettingsCollection.h

@@ -298,6 +298,16 @@ enum class LogsLevel
 };
 using SettingLogsLevel = SettingEnum<LogsLevel>;
 
+// Make it signed for compatibility with DataTypeEnum8
+enum QueryLogElementType : int8_t
+{
+    QUERY_START = 1,
+    QUERY_FINISH = 2,
+    EXCEPTION_BEFORE_START = 3,
+    EXCEPTION_WHILE_PROCESSING = 4,
+};
+using SettingLogQueriesType = SettingEnum<QueryLogElementType>;
+
 
 enum class SettingsBinaryFormat
 {

src/Interpreters/QueryLog.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <Interpreters/SystemLog.h>
+#include <Core/SettingsCollection.h>
 
 
 namespace ProfileEvents
@@ -22,13 +23,7 @@ namespace DB
 /// A struct which will be inserted as row into query_log table
 struct QueryLogElement
 {
-    enum Type : int8_t // Make it signed for compatibility with DataTypeEnum8
-    {
-        QUERY_START = 1,
-        QUERY_FINISH = 2,
-        EXCEPTION_BEFORE_START = 3,
-        EXCEPTION_WHILE_PROCESSING = 4,
-    };
+    using Type = QueryLogElementType;
 
     Type type = QUERY_START;
 

src/Interpreters/executeQuery.cpp

@@ -157,7 +157,7 @@ static void onExceptionBeforeStart(const String & query_for_logging, Context & c
     /// Log the start of query execution into the table if necessary.
     QueryLogElement elem;
 
-    elem.type = QueryLogElement::EXCEPTION_BEFORE_START;
+    elem.type = QueryLogElementType::EXCEPTION_BEFORE_START;
 
     elem.event_time = current_time;
     elem.query_start_time = current_time;
@@ -175,7 +175,7 @@ static void onExceptionBeforeStart(const String & query_for_logging, Context & c
     /// Update performance counters before logging to query_log
     CurrentThread::finalizePerformanceCounters();
 
-    if (settings.log_queries)
+    if (settings.log_queries && elem.type >= settings.log_queries_min_type)
         if (auto query_log = context.getQueryLog())
             query_log->add(elem);
 }
@@ -400,7 +400,7 @@ static std::tuple<ASTPtr, BlockIO> executeQueryImpl(
         {
             QueryLogElement elem;
 
-            elem.type = QueryLogElement::QUERY_START;
+            elem.type = QueryLogElementType::QUERY_START;
 
             elem.event_time = current_time;
             elem.query_start_time = current_time;
@@ -412,7 +412,7 @@ static std::tuple<ASTPtr, BlockIO> executeQueryImpl(
             bool log_queries = settings.log_queries && !internal;
 
             /// Log into system table start of query execution, if need.
-            if (log_queries)
+            if (log_queries && elem.type >= settings.log_queries_min_type)
             {
                 if (settings.log_query_settings)
                     elem.query_settings = std::make_shared<Settings>(context.getSettingsRef());
@@ -422,7 +422,7 @@ static std::tuple<ASTPtr, BlockIO> executeQueryImpl(
             }
 
             /// Also make possible for caller to log successful query finish and exception during execution.
-            auto finish_callback = [elem, &context, log_queries] (IBlockInputStream * stream_in, IBlockOutputStream * stream_out) mutable
+            auto finish_callback = [elem, &context, log_queries, log_queries_min_type = settings.log_queries_min_type] (IBlockInputStream * stream_in, IBlockOutputStream * stream_out) mutable
             {
                 QueryStatus * process_list_elem = context.getProcessListElement();
 
@@ -436,7 +436,7 @@ static std::tuple<ASTPtr, BlockIO> executeQueryImpl(
 
                 double elapsed_seconds = info.elapsed_seconds;
 
-                elem.type = QueryLogElement::QUERY_FINISH;
+                elem.type = QueryLogElementType::QUERY_FINISH;
 
                 elem.event_time = time(nullptr);
                 elem.query_duration_ms = elapsed_seconds * 1000;
@@ -484,19 +484,19 @@ static std::tuple<ASTPtr, BlockIO> executeQueryImpl(
                 elem.thread_ids = std::move(info.thread_ids);
                 elem.profile_counters = std::move(info.profile_counters);
 
-                if (log_queries)
+                if (log_queries && elem.type >= log_queries_min_type)
                 {
                     if (auto query_log = context.getQueryLog())
                         query_log->add(elem);
                 }
             };
 
-            auto exception_callback = [elem, &context, log_queries, quota(quota)] () mutable
+            auto exception_callback = [elem, &context, log_queries, log_queries_min_type = settings.log_queries_min_type, quota(quota)] () mutable
             {
                 if (quota)
                     quota->used(Quota::ERRORS, 1, /* check_exceeded = */ false);
 
-                elem.type = QueryLogElement::EXCEPTION_WHILE_PROCESSING;
+                elem.type = QueryLogElementType::EXCEPTION_WHILE_PROCESSING;
 
                 elem.event_time = time(nullptr);
                 elem.query_duration_ms = 1000 * (elem.event_time - elem.query_start_time);
@@ -529,7 +529,7 @@ static std::tuple<ASTPtr, BlockIO> executeQueryImpl(
                 logException(context, elem);
 
                 /// In case of exception we log internal queries also
-                if (log_queries)
+                if (log_queries && elem.type >= log_queries_min_type)
                 {
                     if (auto query_log = context.getQueryLog())
                         query_log->add(elem);

tests/queries/0_stateless/01231_log_queries_min_type.reference

@@ -0,0 +1,5 @@
+01231_log_queries_min_type/QUERY_START
+2
+01231_log_queries_min_type/EXCEPTION_BEFORE_START
+2
+3

tests/queries/0_stateless/01231_log_queries_min_type.sql

@@ -0,0 +1,15 @@
+set log_queries=1;
+
+select '01231_log_queries_min_type/QUERY_START';
+system flush logs;
+select count() from system.query_log where query like '%01231_log_queries_min_type/%' and query not like '%system.query_log%' and event_date = today() and event_time >= now() - interval 1 minute;
+
+set log_queries_min_type='EXCEPTION_BEFORE_START';
+select '01231_log_queries_min_type/EXCEPTION_BEFORE_START';
+system flush logs;
+select count() from system.query_log where query like '%01231_log_queries_min_type/%' and query not like '%system.query_log%' and event_date = today() and event_time >= now() - interval 1 minute;
+
+set log_queries_min_type='EXCEPTION_WHILE_PROCESSING';
+select '01231_log_queries_min_type/', max(number) from system.numbers limit 1e6 settings max_rows_to_read='100K'; -- { serverError 158; }
+system flush logs;
+select count() from system.query_log where query like '%01231_log_queries_min_type/%' and query not like '%system.query_log%' and event_date = today() and event_time >= now() - interval 1 minute;