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system.symbols

Contains information for introspection of clickhouse binary. It requires the introspection privilege to access. This table is only useful for C++ experts and ClickHouse engineers.

Columns:

  • symbol (String) — Symbol name in the binary. It is mangled. You can apply demangle(symbol) to obtain a readable name.
  • symbol_demangled (Nullable(String)) — Demangled symbol used for XRay instrumentation.
  • function_id (Nullable(Int32)) — Function ID in the XRay instrumentation map.
  • address_begin (UInt64) — Start address of the symbol in the binary.
  • address_end (UInt64) — End address of the symbol in the binary.
  • name (String) — Alias for event.

Example

SELECT * FROM system.symbols WHERE function_id IS NOT NULL LIMIT 5 SETTINGS allow_introspection_functions = 1

Row 1:
──────
symbol:           _Z15isClickhouseAppNSt3__117basic_string_viewIcNS_11char_traitsIcEEEERNS_6vectorIPcNS_9allocatorIS5_EEEE
symbol_demangled: isClickhouseApp(std::__1::basic_string_view<char, std::__1::char_traits<char>>, std::__1::vector<char*, std::__1::allocator<char*>>&)
function_id:      1
address_begin:    219229312 -- 219.23 million
address_end:      219231408 -- 219.23 million

Row 2:
──────
symbol:           main
symbol_demangled: main
function_id:      2
address_begin:    219231872 -- 219.23 million
address_end:      219233485 -- 219.23 million

Row 3:
──────
symbol:           _ZN12_GLOBAL__N_19printHelpEiPPc
symbol_demangled: (anonymous namespace)::printHelp(int, char**)
function_id:      3
address_begin:    219233536 -- 219.23 million
address_end:      219233902 -- 219.23 million

Row 4:
──────
symbol:           _ZNSt3__110filesystem4pathC2B8se210105IPcvEERKT_NS1_6formatE
symbol_demangled: std::__1::filesystem::path::path[abi:se210105]<char*, void>(char* const&, std::__1::filesystem::path::format)
function_id:      4
address_begin:    219234496 -- 219.23 million
address_end:      219234620 -- 219.23 million

Row 5:
──────
symbol:           _ZNSt3__113unordered_setINS_17basic_string_viewIcNS_11char_traitsIcEEEENS_4hashIS4_EENS_8equal_toIS4_EENS_9allocatorIS4_EEEC2ESt16initializer_listIS4_E
symbol_demangled: std::__1::unordered_set<std::__1::basic_string_view<char, std::__1::char_traits<char>>, std::__1::hash<std::__1::basic_string_view<char, std::__1::char_traits<char>>>, std::__1::equal_to<std::__1::basic_string_view<char, std::__1::char_traits<char>>>, std::__1::allocator<std::__1::basic_string_view<char, std::__1::char_traits<char>>>>::unordered_set(std::initializer_list<std::__1::basic_string_view<char, std::__1::char_traits<char>>>)
function_id:      5
address_begin:    219235584 -- 219.24 million
address_end:      219235708 -- 219.24 million