docs/en/operations/system-tables/instrumentation.md
import SystemTableCloud from '@site/docs/_snippets/_system_table_cloud.md';
Contains the instrumentation points using LLVM's XRay feature.
Columns:
id (UInt32) — ID of the instrumentation point.function_id (Int32) — ID assigned to the function in the xray_instr_map section of the ELF binary.function_name (LowCardinality(String)) — Name used to instrument the function.handler (LowCardinality(String)) — Handler type.entry_type (Enum('Entry' = 0, 'Exit' = 1, 'EntryAndExit' = 2)) — Entry type: Entry, Exit or EntryAndExit.symbol (LowCardinality(String)) — Complete and demangled symbol.parameters (Array(Dynamic)) — Parameters for the handler call.Example
SELECT * FROM system.instrumentation FORMAT Vertical;
Row 1:
──────
id: 0
function_id: 231280
function_name: QueryMetricLog::startQuery
handler: log
entry_type: Entry
symbol: DB::QueryMetricLog::startQuery(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>> const&, std::__1::chrono::time_point<std::__1::chrono::system_clock, std::__1::chrono::duration<long long, std::__1::ratio<1l, 1000000l>>>, unsigned long)
parameters: ['test']
Row 2:
──────
id: 1
function_id: 231280
function_name: QueryMetricLog::startQuery
handler: profile
entry_type: EntryAndExit
symbol: DB::QueryMetricLog::startQuery(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>> const&, std::__1::chrono::time_point<std::__1::chrono::system_clock, std::__1::chrono::duration<long long, std::__1::ratio<1l, 1000000l>>>, unsigned long)
parameters: []
Row 3:
──────
id: 2
function_id: 231280
function_name: QueryMetricLog::startQuery
handler: sleep
entry_type: Exit
symbol: DB::QueryMetricLog::startQuery(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>> const&, std::__1::chrono::time_point<std::__1::chrono::system_clock, std::__1::chrono::duration<long long, std::__1::ratio<1l, 1000000l>>>, unsigned long)
parameters: [0.3]
3 rows in set. Elapsed: 0.302 sec.
See also