Built-in Functions

These are functions built into C++ which reduce the amount of boilerplate which needs to be written in SQL.

Profile Functions

STACK_FROM_STACK_PROFILE_FRAME

STACK_FROM_STACK_PROFILE_FRAME(frame_id)

Description

Creates a stack with just the frame referenced by frame_id (reference to the stack_profile_frame table)

Return Type

BYTES

Arguments

Argument Type Description
frame_id StackProfileFrameTable::Id reference to the stack_profile_frame table

STACK_FROM_STACK_PROFILE_CALLSITE

STACK_FROM_STACK_PROFILE_CALLSITE(callsite_id)

Description

Creates a stack by taking a callsite_id (reference to the [stack_profile_callsite]](sql-tables.autogen#stack_profile_callsite) table) and generating a list of frames (by walking the [stack_profile_callsite]](sql-tables.autogen#stack_profile_callsite) table)

Return Type

BYTES

Arguments

Argument Type Description
callsite_id StackProfileCallsiteTable::Id reference to the [stack_profile_callsite]](sql-tables.autogen#stack_profile_callsite) table

CAT_STACKS

CAT_STACKS(([root [[,level_1 [, ...]], leaf]])

Description

Creates a Stack by concatenating other Stacks. Also accepts STRING values for which it generates a fake Frame. Null values are just ignored.

Return Type

BYTES

Arguments

Argument Type Description
root BYTES or STRING Stack or STRING for which a fake Frame is generated
... BYTES or STRING Stack or STRING for which a fake Frame is generated
leaf BYTES or STRING Stack or STRING for which a fake Frame is generated

EXPERIMENTAL_PROFILE

EXPERIMENTAL_PROFILE(stack [,sample_type, sample_units, sample_value]*)

Description

Aggregation function that generates a profile in pprof format from the given samples.

Return Type

BYTES (pprof data)

Arguments

Argument Type Description
stack BYTES Stack or string for which a fake Frame is generated
sample_type STRING Type of the sample value (e.g. size, time)
sample_units STRING Units of the sample value (e.g. bytes, count)
sample_value LONG Value for the sample

Multiple samples can be specified.

If only the stack argument is present, a "samples", "count", and 1 are used as defaults for sample_type, sample_units, and sample_value respectively.

Example

CPU profile

SELECT perf_session_id, EXPERIMENTAL_PROFILE( STACK_FROM_STACK_PROFILE_CALLSITE(callsite_id), 'samples', 'count', 1) AS profile FROM perf_sample GROUP BY perf_session_id

Heap profile

SELECT EXPERIMENTAL_PROFILE( CAT_STACKS(heap_name, STACK_FROM_STACK_PROFILE_CALLSITE(callsite_id)), 'count', 'count', count, 'size', 'bytes', size) AS profile FROM heap_profile_allocation WHERE size >= 0 AND count >= 0