这些函数速度较慢，并且可能带来安全风险。
-
安装
clickhouse-common-static-dbg软件包。 - 将 allow_introspection_functions 设置为 1。 出于安全原因，默认情况下内部信息函数处于禁用状态。
addressToLine
此函数速度较慢，并且可能带来安全风险。
- 安装
clickhouse-common-static-dbg软件包。 - 将设置
allow_introspection_functions设为1。
addressToLine(address_of_binary_instruction)
address_of_binary_instruction— 运行中进程内指令的地址。UInt64
/build/obj-x86_64-linux-gnu/../src/Common/ThreadPool.cpp:199。如果找不到调试信息，则返回二进制文件名；如果地址无效，则返回空字符串。String
示例
从 trace_log 系统表中选取第一条字符串
Query
SET allow_introspection_functions=1;
SELECT * FROM system.trace_log LIMIT 1 \G;
Response
-- `trace` 字段包含采样时刻的调用栈信息。
Row 1:
──────
event_date: 2019-11-19
event_time: 2019-11-19 18:57:23
revision: 54429
timer_type: Real
thread_number: 48
query_id: 421b6855-1858-45a5-8f37-f383409d6d72
trace: [140658411141617,94784174532828,94784076370703,94784076372094,94784076361020,94784175007680,140658411116251,140658403895439]
Query
SET allow_introspection_functions=1;
SELECT addressToLine(94784076370703) \G;
Response
行 1:
──────
addressToLine(94784076370703): /build/obj-x86_64-linux-gnu/../src/Common/ThreadPool.cpp:199
Query
-- 本示例中，arrayMap 函数对 trace 数组的每个元素调用 addressToLine 函数进行处理。
-- 处理结果显示在输出的 trace_source_code_lines 列中。
SELECT
arrayStringConcat(arrayMap(x -> addressToLine(x), trace), '\n') AS trace_source_code_lines
FROM system.trace_log
LIMIT 1
\G
Response
Row 1:
──────
trace_source_code_lines: /lib/x86_64-linux-gnu/libpthread-2.27.so
/usr/lib/debug/usr/bin/clickhouse
/build/obj-x86_64-linux-gnu/../src/Common/ThreadPool.cpp:199
/build/obj-x86_64-linux-gnu/../src/Common/ThreadPool.h:155
/usr/include/c++/9/bits/atomic_base.h:551
/usr/lib/debug/usr/bin/clickhouse
/lib/x86_64-linux-gnu/libpthread-2.27.so
/build/glibc-OTsEL5/glibc-2.27/misc/../sysdeps/unix/sysv/linux/x86_64/clone.S:97
addressToLineWithInlines
addressToLine 类似，但会返回一个包含所有内联函数的 Array。
因此，它比 addressToLine 更慢。
要启用此内部信息函数：
- 安装
clickhouse-common-static-dbg软件包。 - 将设置
allow_introspection_functions设为1。
addressToLineWithInlines(address_of_binary_instruction)
address_of_binary_instruction— 运行中进程内某条指令的地址。UInt64
Array(String)
示例
将该函数应用到某个地址
Query
SET allow_introspection_functions=1;
SELECT addressToLineWithInlines(531055181::UInt64);
Response
┌─addressToLineWithInlines(CAST('531055181', 'UInt64'))────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ ['./src/Functions/addressToLineWithInlines.cpp:98','./build_normal_debug/./src/Functions/addressToLineWithInlines.cpp:176:DB::(anonymous namespace)::FunctionAddressToLineWithInlines::implCached(unsigned long) const'] │
└──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘
Query
SET allow_introspection_functions=1;
-- arrayJoin 函数将数组拆分为行
SELECT
ta, addressToLineWithInlines(arrayJoin(trace) AS ta)
FROM system.trace_log
WHERE
query_id = '5e173544-2020-45de-b645-5deebe2aae54';
Response
┌────────ta─┬─addressToLineWithInlines(arrayJoin(trace))───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ 365497529 │ ['./build_normal_debug/./contrib/libcxx/include/string_view:252'] │
│ 365593602 │ ['./build_normal_debug/./src/Common/Dwarf.cpp:191'] │
│ 365593866 │ ['./build_normal_debug/./src/Common/Dwarf.cpp:0'] │
│ 365592528 │ ['./build_normal_debug/./src/Common/Dwarf.cpp:0'] │
│ 365591003 │ ['./build_normal_debug/./src/Common/Dwarf.cpp:477'] │
│ 365590479 │ ['./build_normal_debug/./src/Common/Dwarf.cpp:442'] │
│ 365590600 │ ['./build_normal_debug/./src/Common/Dwarf.cpp:457'] │
│ 365598941 │ ['./build_normal_debug/./src/Common/Dwarf.cpp:0'] │
│ 365607098 │ ['./build_normal_debug/./src/Common/Dwarf.cpp:0'] │
│ 365590571 │ ['./build_normal_debug/./src/Common/Dwarf.cpp:451'] │
│ 365598941 │ ['./build_normal_debug/./src/Common/Dwarf.cpp:0'] │
│ 365607098 │ ['./build_normal_debug/./src/Common/Dwarf.cpp:0'] │
│ 365590571 │ ['./build_normal_debug/./src/Common/Dwarf.cpp:451'] │
│ 365598941 │ ['./build_normal_debug/./src/Common/Dwarf.cpp:0'] │
│ 365607098 │ ['./build_normal_debug/./src/Common/Dwarf.cpp:0'] │
│ 365590571 │ ['./build_normal_debug/./src/Common/Dwarf.cpp:451'] │
│ 365598941 │ ['./build_normal_debug/./src/Common/Dwarf.cpp:0'] │
│ 365597289 │ ['./build_normal_debug/./src/Common/Dwarf.cpp:807'] │
│ 365599840 │ ['./build_normal_debug/./src/Common/Dwarf.cpp:1118'] │
│ 531058145 │ ['./build_normal_debug/./src/Functions/addressToLineWithInlines.cpp:152'] │
│ 531055181 │ ['./src/Functions/addressToLineWithInlines.cpp:98','./build_normal_debug/./src/Functions/addressToLineWithInlines.cpp:176:DB::(anonymous namespace)::FunctionAddressToLineWithInlines::implCached(unsigned long) const'] │
│ 422333613 │ ['./build_normal_debug/./src/Functions/IFunctionAdaptors.h:21'] │
│ 586866022 │ ['./build_normal_debug/./src/Functions/IFunction.cpp:216'] │
│ 586869053 │ ['./build_normal_debug/./src/Functions/IFunction.cpp:264'] │
│ 586873237 │ ['./build_normal_debug/./src/Functions/IFunction.cpp:334'] │
│ 597901620 │ ['./build_normal_debug/./src/Interpreters/ExpressionActions.cpp:601'] │
│ 597898534 │ ['./build_normal_debug/./src/Interpreters/ExpressionActions.cpp:718'] │
│ 630442912 │ ['./build_normal_debug/./src/Processors/Transforms/ExpressionTransform.cpp:23'] │
│ 546354050 │ ['./build_normal_debug/./src/Processors/ISimpleTransform.h:38'] │
│ 626026993 │ ['./build_normal_debug/./src/Processors/ISimpleTransform.cpp:89'] │
│ 626294022 │ ['./build_normal_debug/./src/Processors/Executors/ExecutionThreadContext.cpp:45'] │
│ 626293730 │ ['./build_normal_debug/./src/Processors/Executors/ExecutionThreadContext.cpp:63'] │
│ 626169525 │ ['./build_normal_debug/./src/Processors/Executors/PipelineExecutor.cpp:213'] │
│ 626170308 │ ['./build_normal_debug/./src/Processors/Executors/PipelineExecutor.cpp:178'] │
│ 626166348 │ ['./build_normal_debug/./src/Processors/Executors/PipelineExecutor.cpp:329'] │
│ 626163461 │ ['./build_normal_debug/./src/Processors/Executors/PipelineExecutor.cpp:84'] │
│ 626323536 │ ['./build_normal_debug/./src/Processors/Executors/PullingAsyncPipelineExecutor.cpp:85'] │
│ 626323277 │ ['./build_normal_debug/./src/Processors/Executors/PullingAsyncPipelineExecutor.cpp:112'] │
│ 626323133 │ ['./build_normal_debug/./contrib/libcxx/include/type_traits:3682'] │
│ 626323041 │ ['./build_normal_debug/./contrib/libcxx/include/tuple:1415'] │
└───────────┴──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘
addressToSymbol
addressToSymbol(address_of_binary_instruction)
address_of_binary_instruction— 运行中进程中指令的地址。UInt64
String
示例
从 trace_log 系统表中查询第一条字符串
Query
SET allow_introspection_functions=1;
SELECT * FROM system.trace_log LIMIT 1 \G;
Response
-- `trace` 字段包含采样时刻的调用栈。
Row 1:
──────
event_date: 2019-11-20
event_time: 2019-11-20 16:57:59
revision: 54429
timer_type: Real
thread_number: 48
query_id: 724028bf-f550-45aa-910d-2af6212b94ac
trace: [94138803686098,94138815010911,94138815096522,94138815101224,94138815102091,94138814222988,94138806823642,94138814457211,94138806823642,94138814457211,94138806823642,94138806795179,94138806796144,94138753770094,94138753771646,94138753760572,94138852407232,140399185266395,140399178045583]
Query
SET allow_introspection_functions=1;
SELECT addressToSymbol(94138803686098) \G;
Response
Row 1:
──────
addressToSymbol(94138803686098): _ZNK2DB24IAggregateFunctionHelperINS_20AggregateFunctionSumImmNS_24AggregateFunctionSumDataImEEEEE19addBatchSinglePlaceEmPcPPKNS_7IColumnEPNS_5ArenaE
Query
SET allow_introspection_functions=1;
-- arrayMap 函数对 trace 数组中的每个元素调用 addressToSymbols 函数进行处理。
-- 处理结果显示在输出的 trace_symbols 列中。
SELECT
arrayStringConcat(arrayMap(x -> addressToSymbol(x), trace), '\n') AS trace_symbols
FROM system.trace_log
LIMIT 1
\G
Response
Row 1:
──────
trace_symbols: _ZNK2DB24IAggregateFunctionHelperINS_20AggregateFunctionSumImmNS_24AggregateFunctionSumDataImEEEEE19addBatchSinglePlaceEmPcPPKNS_7IColumnEPNS_5ArenaE
_ZNK2DB10Aggregator21executeWithoutKeyImplERPcmPNS0_28AggregateFunctionInstructionEPNS_5ArenaE
_ZN2DB10Aggregator14executeOnBlockESt6vectorIN3COWINS_7IColumnEE13immutable_ptrIS3_EESaIS6_EEmRNS_22AggregatedDataVariantsERS1_IPKS3_SaISC_EERS1_ISE_SaISE_EERb
_ZN2DB10Aggregator14executeOnBlockERKNS_5BlockERNS_22AggregatedDataVariantsERSt6vectorIPKNS_7IColumnESaIS9_EERS6_ISB_SaISB_EERb
_ZN2DB10Aggregator7executeERKSt10shared_ptrINS_17IBlockInputStreamEERNS_22AggregatedDataVariantsE
_ZN2DB27AggregatingBlockInputStream8readImplEv
_ZN2DB17IBlockInputStream4readEv
_ZN2DB26ExpressionBlockInputStream8readImplEv
_ZN2DB17IBlockInputStream4readEv
_ZN2DB26ExpressionBlockInputStream8readImplEv
_ZN2DB17IBlockInputStream4readEv
_ZN2DB28AsynchronousBlockInputStream9calculateEv
_ZNSt17_Function_handlerIFvvEZN2DB28AsynchronousBlockInputStream4nextEvEUlvE_E9_M_invokeERKSt9_Any_data
_ZN14ThreadPoolImplI20ThreadFromGlobalPoolE6workerESt14_List_iteratorIS0_E
_ZZN20ThreadFromGlobalPoolC4IZN14ThreadPoolImplIS_E12scheduleImplIvEET_St8functionIFvvEEiSt8optionalImEEUlvE1_JEEEOS4_DpOT0_ENKUlvE_clEv
_ZN14ThreadPoolImplISt6threadE6workerESt14_List_iteratorIS0_E
execute_native_thread_routine
start_thread
clone
demangle
addressToSymbol 函数返回。
语法
demangle(symbol)
symbol— 对象文件中的符号。String
String
示例
从 trace_log 系统表中选取第一个字符串
Query
SELECT * FROM system.trace_log LIMIT 1 \G;
Response
-- The `trace` field contains the stack trace at the moment of sampling.
Row 1:
──────
event_date: 2019-11-20
event_time: 2019-11-20 16:57:59
revision: 54429
timer_type: Real
thread_number: 48
query_id: 724028bf-f550-45aa-910d-2af6212b94ac
trace: [94138803686098,94138815010911,94138815096522,94138815101224,94138815102091,94138814222988,94138806823642,94138814457211,94138806823642,94138814457211,94138806823642,94138806795179,94138806796144,94138753770094,94138753771646,94138753760572,94138852407232,140399185266395,140399178045583]
Query
SET allow_introspection_functions=1;
SELECT demangle(addressToSymbol(94138803686098)) \G;
Response
Row 1:
──────
demangle(addressToSymbol(94138803686098)): DB::IAggregateFunctionHelper<DB::AggregateFunctionSum<unsigned long, unsigned long, DB::AggregateFunctionSumData<unsigned long> > >::addBatchSinglePlace(unsigned long, char*, DB::IColumn const**, DB::Arena*) const
Query
SET allow_introspection_functions=1;
-- The arrayMap function allows to process each individual element of the trace array by the demangle function.
-- The result of this processing is shown in the trace_functions column of output.
SELECT
arrayStringConcat(arrayMap(x -> demangle(addressToSymbol(x)), trace), '\n') AS trace_functions
FROM system.trace_log
LIMIT 1
\G
Response
Row 1:
──────
trace_functions: DB::IAggregateFunctionHelper<DB::AggregateFunctionSum<unsigned long, unsigned long, DB::AggregateFunctionSumData<unsigned long> > >::addBatchSinglePlace(unsigned long, char*, DB::IColumn const**, DB::Arena*) const
DB::Aggregator::executeWithoutKeyImpl(char*&, unsigned long, DB::Aggregator::AggregateFunctionInstruction*, DB::Arena*) const
DB::Aggregator::executeOnBlock(...)
DB::Aggregator::executeOnBlock(DB::Block const&, ...)
DB::Aggregator::execute(std::shared_ptr<DB::IBlockInputStream> const&, DB::AggregatedDataVariants&)
DB::AggregatingBlockInputStream::readImpl()
DB::IBlockInputStream::read()
DB::ExpressionBlockInputStream::readImpl()
DB::IBlockInputStream::read()
DB::ExpressionBlockInputStream::readImpl()
DB::IBlockInputStream::read()
DB::AsynchronousBlockInputStream::calculate()
std::_Function_handler<void (), DB::AsynchronousBlockInputStream::next()::{lambda()#1}>::_M_invoke(std::_Any_data const&)
ThreadPoolImpl<ThreadFromGlobalPool>::worker(std::_List_iterator<ThreadFromGlobalPool>)
ThreadFromGlobalPool::ThreadFromGlobalPool<ThreadPoolImpl<ThreadFromGlobalPool>::scheduleImpl<void>(std::function<void ()>, int, std::optional<unsigned long>)::{lambda()#3}>(ThreadPoolImpl<ThreadFromGlobalPool>::scheduleImpl<void>(std::function<void ()>, int, std::optional<unsigned long>)::{lambda()#3}&&)::{lambda()#1}::operator()() const
ThreadPoolImpl<std::thread>::worker(std::_List_iterator<std::thread>)
execute_native_thread_routine
start_thread
clone
isMergeTreePartCoveredBy
isMergeTreePartCoveredBy(nested_part, covering_part)
1；否则返回 0。UInt8
示例
基本示例
Query
WITH 'all_12_25_7_4' AS lhs, 'all_7_100_10_20' AS rhs
SELECT isMergeTreePartCoveredBy(rhs, lhs), isMergeTreePartCoveredBy(lhs, rhs);
Response
┌─isMergeTreePartCoveredBy(rhs, lhs)─┬─isMergeTreePartCoveredBy(lhs, rhs)─┐
│ 0 │ 1 │
└────────────────────────────────────┴────────────────────────────────────┘
logTrace
logTrace(message)
message— 输出到服务器日志中的消息。const String
0。UInt8
示例
基础示例
Query
SELECT logTrace('logTrace message');
Response
┌─logTrace('logTrace message')─┐
│ 0 │
└──────────────────────────────┘
mergeTreePartInfo
MergeTree 分片名称中提取有用值的函数。
语法
mergeTreePartInfo(part_name)
part_name— 要解包的分片名称。String
partition_id、min_block、max_block、level、mutation。Tuple
示例
基础示例
Query
WITH mergeTreePartInfo('all_12_25_7_4') AS info
SELECT info.partition_id, info.min_block, info.max_block, info.level, info.mutation;
Response
┌─info.partition_id─┬─info.min_block─┬─info.max_block─┬─info.level─┬─info.mutation─┐
│ all │ 12 │ 25 │ 7 │ 4 │
└───────────────────┴────────────────┴────────────────┴────────────┴───────────────┘
tid
tid()
- 无。
UInt64
示例
使用示例
Query
SELECT tid();
Response
┌─tid()─┐
│ 3878 │
└───────┘