Just-In-Time (JIT) compilation

Starting from Timeplus Enterprise 2.9, the JIT compilation is enabled by default. For example, if you need to run the following SQL multiple times:

select ts, key, value as v, 1+2*v*v+3*v*v*v as calc from stream

Timeplus will compile the complex SQL expression to machine code to improve the runtime performance. For more technical details of the implementation, please check the blog.

Settings

The following settings can be overridden in the query time using SET key=value. You can also query the current value and description via

select * from system.settings where name like '%to_compile%';

min_count_to_compile_expression

Minimum count of executing same expression before it is get compiled.

uint64 type. Default to 3.

min_count_to_compile_aggregate_expression

The minimum number of identical aggregate expressions to start JIT-compilation. Works only if the compile_aggregate_expressions setting is enabled.

uint64 type. Default to 3.

min_count_to_compile_sort_description

The number of identical sort descriptions before they are JIT-compiled.

uint64 type. Default to 3.

Monitoring

You can run the following query to check the counts of JIT events:

select * from system.events where event like 'Compile%';