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pgsql: Doc: improve description of window function processing.
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* pgsql: Doc: improve description of window function processing.
@ 2025-03-10 14:23 Tom Lane <[email protected]>
  0 siblings, 0 replies; 6+ messages in thread

From: Tom Lane @ 2025-03-10 14:23 UTC (permalink / raw)
  To: [email protected]

Doc: improve description of window function processing.

The previous wording talked about a "single pass over the data",
which can be read as promising more than intended (to wit, that only
one WindowAgg plan node will be used).  What we promise is only what
the SQL spec requires, namely that the data not get re-sorted between
window functions with compatible PARTITION BY/ORDER BY clauses.
Adjust the wording in hopes of making this clearer.

Reported-by: Christopher Inokuchi <[email protected]>
Author: Tom Lane <[email protected]>
Reviewed-by: David G. Johnston <[email protected]>
Discussion: https://postgr.es/m/CABde6B5va2wMsnM79u_x=n9KUgfKQje_pbLROEBmA9Ru5XWidw@mail.gmail.com
Backpatch-through: 13

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/9f87e2593febf0ff024c11b9a97703bce0eee7be

Modified Files
--------------
doc/src/sgml/queries.sgml | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)



^ permalink  raw  reply  [nested|flat] 6+ messages in thread

* pgsql: Doc: improve description of window function processing.
@ 2025-03-10 14:23 Tom Lane <[email protected]>
  0 siblings, 0 replies; 6+ messages in thread

From: Tom Lane @ 2025-03-10 14:23 UTC (permalink / raw)
  To: [email protected]

Doc: improve description of window function processing.

The previous wording talked about a "single pass over the data",
which can be read as promising more than intended (to wit, that only
one WindowAgg plan node will be used).  What we promise is only what
the SQL spec requires, namely that the data not get re-sorted between
window functions with compatible PARTITION BY/ORDER BY clauses.
Adjust the wording in hopes of making this clearer.

Reported-by: Christopher Inokuchi <[email protected]>
Author: Tom Lane <[email protected]>
Reviewed-by: David G. Johnston <[email protected]>
Discussion: https://postgr.es/m/CABde6B5va2wMsnM79u_x=n9KUgfKQje_pbLROEBmA9Ru5XWidw@mail.gmail.com
Backpatch-through: 13

Branch
------
REL_16_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/778f9dd0d2aa84f5c67f0e257a175c3c99d0dc5e

Modified Files
--------------
doc/src/sgml/queries.sgml | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)



^ permalink  raw  reply  [nested|flat] 6+ messages in thread

* pgsql: Doc: improve description of window function processing.
@ 2025-03-10 14:23 Tom Lane <[email protected]>
  0 siblings, 0 replies; 6+ messages in thread

From: Tom Lane @ 2025-03-10 14:23 UTC (permalink / raw)
  To: [email protected]

Doc: improve description of window function processing.

The previous wording talked about a "single pass over the data",
which can be read as promising more than intended (to wit, that only
one WindowAgg plan node will be used).  What we promise is only what
the SQL spec requires, namely that the data not get re-sorted between
window functions with compatible PARTITION BY/ORDER BY clauses.
Adjust the wording in hopes of making this clearer.

Reported-by: Christopher Inokuchi <[email protected]>
Author: Tom Lane <[email protected]>
Reviewed-by: David G. Johnston <[email protected]>
Discussion: https://postgr.es/m/CABde6B5va2wMsnM79u_x=n9KUgfKQje_pbLROEBmA9Ru5XWidw@mail.gmail.com
Backpatch-through: 13

Branch
------
REL_15_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/2db974e40df64b946e172736547f001162439149

Modified Files
--------------
doc/src/sgml/queries.sgml | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)



^ permalink  raw  reply  [nested|flat] 6+ messages in thread

* pgsql: Doc: improve description of window function processing.
@ 2025-03-10 14:23 Tom Lane <[email protected]>
  0 siblings, 0 replies; 6+ messages in thread

From: Tom Lane @ 2025-03-10 14:23 UTC (permalink / raw)
  To: [email protected]

Doc: improve description of window function processing.

The previous wording talked about a "single pass over the data",
which can be read as promising more than intended (to wit, that only
one WindowAgg plan node will be used).  What we promise is only what
the SQL spec requires, namely that the data not get re-sorted between
window functions with compatible PARTITION BY/ORDER BY clauses.
Adjust the wording in hopes of making this clearer.

Reported-by: Christopher Inokuchi <[email protected]>
Author: Tom Lane <[email protected]>
Reviewed-by: David G. Johnston <[email protected]>
Discussion: https://postgr.es/m/CABde6B5va2wMsnM79u_x=n9KUgfKQje_pbLROEBmA9Ru5XWidw@mail.gmail.com
Backpatch-through: 13

Branch
------
REL_13_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/6841118216ef25fcda428985eb337c6e0440bffc

Modified Files
--------------
doc/src/sgml/queries.sgml | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)



^ permalink  raw  reply  [nested|flat] 6+ messages in thread

* pgsql: Doc: improve description of window function processing.
@ 2025-03-10 14:23 Tom Lane <[email protected]>
  0 siblings, 0 replies; 6+ messages in thread

From: Tom Lane @ 2025-03-10 14:23 UTC (permalink / raw)
  To: [email protected]

Doc: improve description of window function processing.

The previous wording talked about a "single pass over the data",
which can be read as promising more than intended (to wit, that only
one WindowAgg plan node will be used).  What we promise is only what
the SQL spec requires, namely that the data not get re-sorted between
window functions with compatible PARTITION BY/ORDER BY clauses.
Adjust the wording in hopes of making this clearer.

Reported-by: Christopher Inokuchi <[email protected]>
Author: Tom Lane <[email protected]>
Reviewed-by: David G. Johnston <[email protected]>
Discussion: https://postgr.es/m/CABde6B5va2wMsnM79u_x=n9KUgfKQje_pbLROEBmA9Ru5XWidw@mail.gmail.com
Backpatch-through: 13

Branch
------
REL_14_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/e7d29d1fac822d5a3dc2f7fafa5bd80a742f27af

Modified Files
--------------
doc/src/sgml/queries.sgml | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)



^ permalink  raw  reply  [nested|flat] 6+ messages in thread

* pgsql: Doc: improve description of window function processing.
@ 2025-03-10 14:23 Tom Lane <[email protected]>
  0 siblings, 0 replies; 6+ messages in thread

From: Tom Lane @ 2025-03-10 14:23 UTC (permalink / raw)
  To: [email protected]

Doc: improve description of window function processing.

The previous wording talked about a "single pass over the data",
which can be read as promising more than intended (to wit, that only
one WindowAgg plan node will be used).  What we promise is only what
the SQL spec requires, namely that the data not get re-sorted between
window functions with compatible PARTITION BY/ORDER BY clauses.
Adjust the wording in hopes of making this clearer.

Reported-by: Christopher Inokuchi <[email protected]>
Author: Tom Lane <[email protected]>
Reviewed-by: David G. Johnston <[email protected]>
Discussion: https://postgr.es/m/CABde6B5va2wMsnM79u_x=n9KUgfKQje_pbLROEBmA9Ru5XWidw@mail.gmail.com
Backpatch-through: 13

Branch
------
REL_17_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/0f27bd14e48026fe4ddf131a531b230680868aaf

Modified Files
--------------
doc/src/sgml/queries.sgml | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)



^ permalink  raw  reply  [nested|flat] 6+ messages in thread


end of thread, other threads:[~2025-03-10 14:23 UTC | newest]

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2025-03-10 14:23 pgsql: Doc: improve description of window function processing. Tom Lane <[email protected]>
2025-03-10 14:23 pgsql: Doc: improve description of window function processing. Tom Lane <[email protected]>
2025-03-10 14:23 pgsql: Doc: improve description of window function processing. Tom Lane <[email protected]>
2025-03-10 14:23 pgsql: Doc: improve description of window function processing. Tom Lane <[email protected]>

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