126976a8ff
Commit 1811f1af9 put outer tuples with null join keys into a
tuplestore and emitted them at the end of the batch, which risks
expensive spills to disk if there are a lot of them. It's difficult
to avoid the tuplestore in a multi-batch parallel join. But in the
non-parallel and single-batch cases we can just emit such tuples
immediately, at the tiny cost of propagating the "is-null" result
flag one call level further up. This avoids a performance regression
from v18 for such cases.
Author: shihao zhong <zhong950419@gmail.com>
Co-authored-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAGRkXqTgugmYrtnP_11NjL_GCXwAfzVfm5WKUNFsfZOzxDF2rA@mail.gmail.com
Backpatch-through: 19
PostgreSQL Database Management System
This directory contains the source code distribution of the PostgreSQL database management system.
PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings.
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