Database Administrators Stack Exchange
Database Administrators Stack Exchange

Questions tagged [jit]

Just-In-Time (JIT) compilation is a way of executing computer code that involves compilation during execution of a program – at run time – rather than prior to execution. Used in some database systems to accelerate performance.

JIT compilation is used by some database systems such as Postgres to accelerate execution of certain tasks that generate code on-the-fly.

For example, Postgres uses JIT compilation to speed up the bytecode emitted by the expression evaluator for the criteria in a SQL WHERE clause. Postgres also uses JIT compilation for tuple deforming.

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Handling performance problems with jit in postgres 12

tl;dr: What is the best way to handle performance decrease caused by jit? Background: Lately I have migrated from postgres 11 to 12 and noticed, that some queries / procedures run considerably slower. I did some research and tested different…
Andronicus
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How to tell if Postgres was built with the option to include LLVM technology for JIT?

Postgres 11 gained the ability to perform Just-in-Time Compilation (JIT) based on LLVM technology. The manual notes that this feature depends on Postgres having been built with the --with-llvm option. ➥ How can one verify their build of Postgres…
Basil Bourque
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Postgres 13/14 JIT execution increase execution time of query considerably

I have a complex DB query that I run on different systems with identical specs, but different OS (CentOS7 vs. Debian 11). The Postgres version is 13.7, but I also tried with 14.4. I get vastly different execution times for the query on both systems…
spa
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Queries on large database kill connection to the server, works with LIMIT

I'm trying to run queries on a large-ish database without killing the connection to the server. I'm using Postgres 12.1 on a mac with 16gb of memory, and about 40gb of free disk. The database is 78gb according to pg_database_size with the largest…
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pg_jit_available showing 'false' and jit not working, but config file seems set up properly

I am trying to turn on JIT for testing purposes on a Postgresql 12 server, it was off before. My postgresql.conf has the following properties activated (basically all default values): jit = on jit_above_cost =…
bakamitai666
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