Instead of WAL-logging every modification during the build separately,
first build the index without any WAL-logging, and make a separate pass
through the index at the end, to write all pages to the WAL. This
significantly reduces the amount of WAL generated, and is usually also
faster, despite the extra I/O needed for the extra scan through the index.
WAL generated this way is also faster to replay.
For GiST, the LSN-NSN interlock makes this a little tricky. All pages must
be marked with a valid (i.e. non-zero) LSN, so that the parent-child
LSN-NSN interlock works correctly. We now use magic value 1 for that during
index build. Change the fake LSN counter to begin from 1000, so that 1 is
safely smaller than any real or fake LSN. 2 would've been enough for our
purposes, but let's reserve a bigger range, in case we need more special
values in the future.
Author: Anastasia Lubennikova, Andrey V. Lepikhov
Reviewed-by: Heikki Linnakangas, Dmitry Dolgov
When GIN vacuum deletes a posting tree page, it assumes that no concurrent
searchers can access it, thanks to ginStepRight() locking two pages at once.
However, since 9.4 searches can skip parts of posting trees descending from the
root. That leads to the risk that page is deleted and reclaimed before
concurrent search can access it.
This commit prevents the risk of above by waiting for every transaction, which
might wait to reference this page, to finish. Due to binary compatibility
we can't change GinPageOpaqueData to store corresponding transaction id.
Instead we reuse page header pd_prune_xid field, which is unused in index pages.
Discussion: https://postgr.es/m/31a702a.14dd.166c1366ac1.Coremail.chjischj%40163.com
Author: Andrey Borodin, Alexander Korotkov
Reviewed-by: Alexander Korotkov
Backpatch-through: 9.4
Change pg_bsd_indent to follow upstream rules for placement of comments
to the right of code, and remove pgindent hack that caused comments
following #endif to not obey the general rule.
Commit e3860ffa4d wasn't actually using
the published version of pg_bsd_indent, but a hacked-up version that
tried to minimize the amount of movement of comments to the right of
code. The situation of interest is where such a comment has to be
moved to the right of its default placement at column 33 because there's
code there. BSD indent has always moved right in units of tab stops
in such cases --- but in the previous incarnation, indent was working
in 8-space tab stops, while now it knows we use 4-space tabs. So the
net result is that in about half the cases, such comments are placed
one tab stop left of before. This is better all around: it leaves
more room on the line for comment text, and it means that in such
cases the comment uniformly starts at the next 4-space tab stop after
the code, rather than sometimes one and sometimes two tabs after.
Also, ensure that comments following #endif are indented the same
as comments following other preprocessor commands such as #else.
That inconsistency turns out to have been self-inflicted damage
from a poorly-thought-through post-indent "fixup" in pgindent.
This patch is much less interesting than the first round of indent
changes, but also bulkier, so I thought it best to separate the effects.
Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org
Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
The new indent version includes numerous fixes thanks to Piotr Stefaniak.
The main changes visible in this commit are:
* Nicer formatting of function-pointer declarations.
* No longer unexpectedly removes spaces in expressions using casts,
sizeof, or offsetof.
* No longer wants to add a space in "struct structname *varname", as
well as some similar cases for const- or volatile-qualified pointers.
* Declarations using PG_USED_FOR_ASSERTS_ONLY are formatted more nicely.
* Fixes bug where comments following declarations were sometimes placed
with no space separating them from the code.
* Fixes some odd decisions for comments following case labels.
* Fixes some cases where comments following code were indented to less
than the expected column 33.
On the less good side, it now tends to put more whitespace around typedef
names that are not listed in typedefs.list. This might encourage us to
put more effort into typedef name collection; it's not really a bug in
indent itself.
There are more changes coming after this round, having to do with comment
indentation and alignment of lines appearing within parentheses. I wanted
to limit the size of the diffs to something that could be reviewed without
one's eyes completely glazing over, so it seemed better to split up the
changes as much as practical.
Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org
Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
The xlog-specific headers need to be included in both frontend code -
specifically, pg_waldump - and the backend, but the remainder of the
private headers for each index are only needed by the backend. By
splitting the xlog stuff out into separate headers, pg_waldump pulls
in fewer backend headers, which is a good thing.
Patch by me, reviewed by Michael Paquier and Andres Freund, per a
complaint from Dilip Kumar.
Discussion: http://postgr.es/m/CA+TgmoZ=F=GkxV0YEv-A8tb+AEGy_Qa7GSiJ8deBKFATnzfEug@mail.gmail.com
Heikki Linnakangas
Bruce Momjian
Alexander Korotkov
Tom Lane
Robert Haas