system.symbols

System table useful for C++ experts and ClickHouse engineers containing information for introspection of the clickhouse binary.

Description

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.
• address_begin (UInt64) — Start address of the symbol in the binary.
• address_end (UInt64) — End address of the symbol in the binary.

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