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Commit Graph

343 Commits

Author SHA1 Message Date
Bruce Momjian
3282c4c136 README change: update for hash access method
Reported-by: Thomas Munro, Justin Pryzby

Discussion: https://postgr.es/m/CAEepm=1_682z-09DNHj4GkCJAqWK-D6h9Oq5ea84T1oqq1-Utg@mail.gmail.com
2018-03-29 14:38:39 -04:00
Tom Lane
d79e7e92bf Remove redundant IndexTupleDSize macro.
Use IndexTupleSize everywhere, instead.  Also, remove IndexTupleSize's
internal typecast, as that's not really needed and might mask coding
errors.  Change some pointer variable datatypes in the call sites
to compensate for that and make it clearer what we're assuming.

Ildar Musin, Robert Haas, Stephen Frost

Discussion: https://postgr.es/m/0274288e-9e88-13b6-c61c-7b36928bf221@postgrespro.ru
2018-02-28 19:25:54 -05:00
Robert Haas
9da0cc3528 Support parallel btree index builds.
To make this work, tuplesort.c and logtape.c must also support
parallelism, so this patch adds that infrastructure and then applies
it to the particular case of parallel btree index builds.  Testing
to date shows that this can often be 2-3x faster than a serial
index build.

The model for deciding how many workers to use is fairly primitive
at present, but it's better than not having the feature.  We can
refine it as we get more experience.

Peter Geoghegan with some help from Rushabh Lathia.  While Heikki
Linnakangas is not an author of this patch, he wrote other patches
without which this feature would not have been possible, and
therefore the release notes should possibly credit him as an author
of this feature.  Reviewed by Claudio Freire, Heikki Linnakangas,
Thomas Munro, Tels, Amit Kapila, me.

Discussion: http://postgr.es/m/CAM3SWZQKM=Pzc=CAHzRixKjp2eO5Q0Jg1SoFQqeXFQ647JiwqQ@mail.gmail.com
Discussion: http://postgr.es/m/CAH2-Wz=AxWqDoVvGU7dq856S4r6sJAj6DBn7VMtigkB33N5eyg@mail.gmail.com
2018-02-02 13:32:44 -05:00
Robert Haas
ad25a6b1f2 Fix possible failure to mark hash metapage dirty.
Report and suggested fix by Lixian Zou.  Amit Kapila put it
in the form of a patch and reviewed.

Discussion: http://postgr.es/m/151739848647.1239.12528851873396651946@wrigleys.postgresql.org
2018-02-01 15:23:45 -05:00
Bruce Momjian
9d4649ca49 Update copyright for 2018
Backpatch-through: certain files through 9.3
2018-01-02 23:30:12 -05:00
Peter Eisentraut
2eb4a831e5 Change TRUE/FALSE to true/false
The lower case spellings are C and C++ standard and are used in most
parts of the PostgreSQL sources.  The upper case spellings are only used
in some files/modules.  So standardize on the standard spellings.

The APIs for ICU, Perl, and Windows define their own TRUE and FALSE, so
those are left as is when using those APIs.

In code comments, we use the lower-case spelling for the C concepts and
keep the upper-case spelling for the SQL concepts.

Reviewed-by: Michael Paquier <michael.paquier@gmail.com>
2017-11-08 11:37:28 -05:00
Tom Lane
4c11d2c559 Flag index metapages as standard-format in xlog.c calls.
btree, hash, and bloom indexes all set up their metapages in standard
format (that is, with pd_lower and pd_upper correctly delimiting the
unused area); but they mostly didn't inform the xlog routines of this.
When calling log_newpage[_buffer], this is bad because it loses the
opportunity to compress unused data out of the WAL record.  When
calling XLogRegisterBuffer, it's not such a performance problem because
all of these call sites also use REGBUF_WILL_INIT, preventing an FPI
image from being written.  But it's still a good idea to provide the
flag when relevant, because that aids WAL consistency checking.

This completes the project of getting all the in-core index AMs to
handle their metapage WAL operations similarly.

Amit Kapila, reviewed by Michael Paquier

Discussion: https://postgr.es/m/0d273805-0e9e-ec1a-cb84-d4da400b8f85@lab.ntt.co.jp
2017-11-03 16:31:32 -04:00
Robert Haas
22c5e73562 Remove lsn from HashScanPosData.
This was intended as infrastructure for weakening VACUUM's locking
requirements, similar to what was done for btree indexes in commit
2ed5b87f96.  However, for hash indexes,
it seems that the improvements which are possible are actually
extremely marginal.  Furthermore, performing the LSN cross-check will
end up skipping cleanup far more often than is necessary; we only care
about page modifications due to a VACUUM, but the LSN check will fail
if ANY modification has occurred.  So, rather than pressing forward
with that "optimization", just rip the LSN field out.

Patch by me, reviewed by Ashutosh Sharma and Amit Kapila

Discussion: http://postgr.es/m/CAA4eK1JxqqcuC5Un7YLQVhOYSZBS+t=3xqZuEkt5RyquyuxpwQ@mail.gmail.com
2017-09-26 09:16:45 -04:00
Robert Haas
79a4a665c0 Fix trivial mistake in README.
You might think I (Robert) could manage to count to five without
messing it up, but if you did, you would be wrong.

Amit Kapila

Discussion: http://postgr.es/m/CAA4eK1JxqqcuC5Un7YLQVhOYSZBS+t=3xqZuEkt5RyquyuxpwQ@mail.gmail.com
2017-09-26 09:01:43 -04:00
Robert Haas
6a2fa09c0c For wal_consistency_checking, mask page checksum as well as page LSN.
If the LSN is different, the checksum will be different, too.

Ashwin Agrawal, reviewed by Michael Paquier and Kuntal Ghosh

Discussion: http://postgr.es/m/CALfoeis5iqrAU-+JAN+ZzXkpPr7+-0OAGv7QUHwFn=-wDy4o4Q@mail.gmail.com
2017-09-22 14:28:22 -04:00
Robert Haas
7c75ef5715 hash: Implement page-at-a-time scan.
Commit 09cb5c0e7d added a similar
optimization to btree back in 2006, but nobody bothered to implement
the same thing for hash indexes, probably because they weren't
WAL-logged and had lots of other performance problems as well.  As
with the corresponding btree case, this eliminates the problem of
potentially needing to refind our position within the page, and cuts
down on pin/unpin traffic as well.

Ashutosh Sharma, reviewed by Alexander Korotkov, Jesper Pedersen,
Amit Kapila, and me.  Some final edits to comments and README by
me.

Discussion: http://postgr.es/m/CAE9k0Pm3KTx93K8_5j6VMzG4h5F+SyknxUwXrN-zqSZ9X8ZS3w@mail.gmail.com
2017-09-22 13:56:27 -04:00
Robert Haas
81c5e46c49 Introduce 64-bit hash functions with a 64-bit seed.
This will be useful for hash partitioning, which needs a way to seed
the hash functions to avoid problems such as a hash index on a hash
partitioned table clumping all values into a small portion of the
bucket space; it's also useful for anything that wants a 64-bit hash
value rather than a 32-bit hash value.

Just in case somebody wants a 64-bit hash value that is compatible
with the existing 32-bit hash values, make the low 32-bits of the
64-bit hash value match the 32-bit hash value when the seed is 0.

Robert Haas and Amul Sul

Discussion: http://postgr.es/m/CA+Tgmoafx2yoJuhCQQOL5CocEi-w_uG4S2xT0EtgiJnPGcHW3g@mail.gmail.com
2017-08-31 22:21:21 -04:00
Tom Lane
21d304dfed Final pgindent + perltidy run for v10. 2017-08-14 17:29:33 -04:00
Robert Haas
ff98a5e1e4 hash: Immediately after a bucket split, try to clean the old bucket.
If it works, then we won't be storing two copies of all the tuples
that were just moved.  If not, VACUUM will still take care of it
eventually.  Per a report from AP and analysis from Amit Kapila, it
seems that a bulk load can cause splits fast enough that VACUUM won't
deal with the problem in time to prevent bloat.

Amit Kapila; I rewrote the comment.

Discussion: http://postgr.es/m/20170704105728.mwb72jebfmok2nm2@zip.com.au
2017-08-04 19:33:01 -04:00
Robert Haas
09c2e7cd2f hash: Fix write-ahead logging bugs related to init forks.
One, logging for CREATE INDEX was oblivious to the fact that when
an unlogged table is created, *only* operations on the init fork
should be logged.

Two, init fork buffers need to be flushed after they are written;
otherwise, a filesystem-level copy following recovery may do the
wrong thing.  (There may be a better fix for this issue than the
one used here, but this is transposed from the similar logic already
present in XLogReadBufferForRedoExtended, and a broader refactoring
after beta2 seems inadvisable.)

Amit Kapila, reviewed by Ashutosh Sharma, Kyotaro Horiguchi,
and Michael Paquier

Discussion: http://postgr.es/m/CAA4eK1JpcMsEtOL_J7WODumeEfyrPi7FPYHeVdS7fyyrCrgp4w@mail.gmail.com
2017-07-17 12:03:35 -04:00
Tom Lane
382ceffdf7 Phase 3 of pgindent updates.
Don't move parenthesized lines to the left, even if that means they
flow past the right margin.

By default, BSD indent lines up statement continuation lines that are
within parentheses so that they start just to the right of the preceding
left parenthesis.  However, traditionally, if that resulted in the
continuation line extending to the right of the desired right margin,
then indent would push it left just far enough to not overrun the margin,
if it could do so without making the continuation line start to the left of
the current statement indent.  That makes for a weird mix of indentations
unless one has been completely rigid about never violating the 80-column
limit.

This behavior has been pretty universally panned by Postgres developers.
Hence, disable it with indent's new -lpl switch, so that parenthesized
lines are always lined up with the preceding left paren.

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
2017-06-21 15:35:54 -04:00
Tom Lane
c7b8998ebb Phase 2 of pgindent updates.
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
2017-06-21 15:19:25 -04:00
Tom Lane
e3860ffa4d Initial pgindent run with pg_bsd_indent version 2.0.
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
2017-06-21 14:39:04 -04:00
Alvaro Herrera
e6785a5ca1 Fix wording in amvalidate error messages
Remove some gratuituous message differences by making the AM name
previously embedded in each message be a %s instead.  While at it, get
rid of terminology that's unclear and unnecessary in one message.

Discussion: https://postgr.es/m/20170523001557.bq2hbq7hxyvyw62q@alvherre.pgsql
2017-05-30 15:45:42 -04:00
Magnus Hagander
312bac54cc Fix typo in comment
Author: Masahiko Sawada
2017-05-22 09:10:02 +02:00
Bruce Momjian
a6fd7b7a5f Post-PG 10 beta1 pgindent run
perltidy run not included.
2017-05-17 16:31:56 -04:00
Robert Haas
a5775991bb Remove no-longer-needed compatibility code for hash indexes.
Because commit ea69a0dead bumped the
HASH_VERSION, we don't need to worry about PostgreSQL 10 seeing
bucket pages from earlier versions.

Amit Kapila

Discussion: http://postgr.es/m/CAA4eK1LAo4DGwh+mi-G3U8Pj1WkBBeFL38xdCnUHJv1z4bZFkQ@mail.gmail.com
2017-05-09 23:44:21 -04:00
Tom Lane
083dc95a14 More cleanup of manipulations of hash indexes' hasho_flag field.
Not much point in defining test macros for the flag bits if we
don't use 'em.

Amit Kapila
2017-04-15 14:11:15 -04:00
Tom Lane
2040bb4a0b Clean up manipulations of hash indexes' hasho_flag field.
Standardize on testing a hash index page's type by doing
	(opaque->hasho_flag & LH_PAGE_TYPE) == LH_xxx_PAGE
Various places were taking shortcuts like
	opaque->hasho_flag & LH_BUCKET_PAGE
which while not actually wrong, is still bad practice because
it encourages use of
	opaque->hasho_flag & LH_UNUSED_PAGE
which *is* wrong (LH_UNUSED_PAGE == 0, so the above is constant false).
hash_xlog.c's hash_mask() contained such an incorrect test.

This also ensures that we mask out the additional flag bits that
hasho_flag has accreted since 9.6.  pgstattuple's pgstat_hash_page(),
for one, was failing to do that and was thus actively broken.

Also fix assorted comments that hadn't been updated to reflect the
extended usage of hasho_flag, and fix some macros that were testing
just "(hasho_flag & bit)" to use the less dangerous, project-approved
form "((hasho_flag & bit) != 0)".

Coverity found the bug in hash_mask(); I noted the one in
pgstat_hash_page() through code reading.
2017-04-14 17:04:25 -04:00
Robert Haas
633e15ea0f Fix pageinspect failures on hash indexes.
Make every page in a hash index which isn't all-zeroes have a valid
special space, so that tools like pageinspect don't error out.

Also, make pageinspect cope with all-zeroes pages, because
_hash_alloc_buckets can leave behind large numbers of those until
they're consumed by splits.

Ashutosh Sharma and Robert Haas, reviewed by Amit Kapila.
Original trouble report from Jeff Janes.

Discussion: http://postgr.es/m/CAMkU=1y6NjKmqbJ8wLMhr=F74WzcMALYWcVFhEpm7i=mV=XsOg@mail.gmail.com
2017-04-05 14:18:15 -04:00
Robert Haas
75a1cbdc3c hash: Fix write-ahead logging bug.
The size of the data is not the same thing as the size of the size of
the data.

Reported off-list by Tushar Ahuja.  Fix by Ashutosh Sharma, reviewed
by Amit Kapila.

Discussion: http://postgr.es/m/CAE9k0PnmPDXfvf8HDObme7q_Ewc4E26ukHXUBPySoOs0ObqqaQ@mail.gmail.com
2017-04-05 11:45:35 -04:00
Robert Haas
b38006ef6d Fix formula in _hash_spareindex.
This was correct in earlier versions of the patch that lead to
commit ea69a0dead, but somehow got
broken in the last version which I actually committed.

Mithun Cy, per an off-list report from Ashutosh Sharma

Discussion: http://postgr.es/m/CAD__OujbAwNU71v1y-RoQxZ8LZ6-V2UFTkex3v34MK6uZ3Xb5w@mail.gmail.com
2017-04-04 07:45:04 -04:00
Robert Haas
ea69a0dead Expand hash indexes more gradually.
Since hash indexes typically have very few overflow pages, adding a
new splitpoint essentially doubles the on-disk size of the index,
which can lead to large and abrupt increases in disk usage (and
perhaps long delays on occasion).  To mitigate this problem to some
degree, divide larger splitpoints into four equal phases.  This means
that, for example, instead of growing from 4GB to 8GB all at once, a
hash index will now grow from 4GB to 5GB to 6GB to 7GB to 8GB, which
is perhaps still not as smooth as we'd like but certainly an
improvement.

This changes the on-disk format of the metapage, so bump HASH_VERSION
from 2 to 3.  This will force a REINDEX of all existing hash indexes,
but that's probably a good idea anyway.  First, hash indexes from
pre-10 versions of PostgreSQL could easily be corrupted, and we don't
want to confuse corruption carried over from an older release with any
corruption caused despite the new write-ahead logging in v10.  Second,
it will let us remove some backward-compatibility code added by commit
293e24e507.

Mithun Cy, reviewed by Amit Kapila, Jesper Pedersen and me.  Regression
test outputs updated by me.

Discussion: http://postgr.es/m/CAD__OuhG6F1gQLCgMQNnMNgoCvOLQZz9zKYJQNYvYmmJoM42gA@mail.gmail.com
Discussion: http://postgr.es/m/CA+TgmoYty0jCf-pa+m+vYUJ716+AxM7nv_syvyanyf5O-L_i2A@mail.gmail.com
2017-04-03 23:46:33 -04:00
Robert Haas
93cd7684ee Properly acquire buffer lock for page-at-a-time hash vacuum.
In a couple of places, _hash_kill_items was mistakenly called with
the buffer lock not held.  Repair.

Ashutosh Sharma, per a report from Andreas Seltenreich

Discussion: http://postgr.es/m/87o9wo8o0j.fsf@credativ.de
2017-04-03 22:26:06 -04:00
Robert Haas
c4c51541e2 Still more code review for single-page hash vacuuming.
Most seriously, fix use of incorrect block ID, per a report from
Jeff Janes that it causes a crash and a diagnosis from Amit Kapila.

Improve consistency between the hash and btree versions of this
code by adding back a PANIC that btree has, and by registering
data in the xlog record in the same way, per complaints from
Jeff Janes and Amit Kapila.

Tidy up some minor cosmetic points, per complaints from Amit
Kapila.

Patch by Ashutosh Sharma, reviewed by Amit Kapila, and tested by
Jeff Janes.

Discussion: http://postgr.es/m/CAMkU=1w-9Qe=Ff1o6bSaXpNO9wqpo7_9GL8_CVhw4BoVVHasqg@mail.gmail.com
2017-03-27 12:51:10 -04:00
Robert Haas
f0a6046bcb Fix comment.
Cut-and-paste led to something silly.

Ashutosh Sharma, reviewed by Amit Kapila and by me

Discussion: http://postgr.es/m/CAE9k0PmUbvQSBY7kwN_OkuqBYyHRXBX-c1ZkuAgR5vgF0GeWzQ@mail.gmail.com
2017-03-26 22:15:50 -04:00
Robert Haas
9abbf4727d Another fix for single-page hash index vacuum.
The WAL consistency checking code needed to be updated for the new
page status bit, but that didn't get done previously.

Ashutosh Sharma, reviewed by Amit Kapila

Discussion: http://postgr.es/m/CAA4eK1LP_oz4EfMen14OjJuzN5CqPdfRkFFuA-MfkcfeE8zGyg@mail.gmail.com
2017-03-20 15:55:27 -04:00
Robert Haas
953477ca35 Fixes for single-page hash index vacuum.
Clear LH_PAGE_HAS_DEAD_TUPLES during replay, similar to what gets done
for btree.  Update hashdesc.c for xl_hash_vacuum_one_page.

Oversights in commit 6977b8b7f4 spotted
by Amit Kapila.  Patch by Ashutosh Sharma.

Bump WAL version.  The original patch to make hash indexes write-ahead
logged probably should have done this, and the single page vacuuming
patch probably should have done it again, but better late than never.

Discussion: http://postgr.es/m/CAA4eK1Kd=mJ9xreovcsh0qMiAj-QqCphHVQ_Lfau1DR9oVjASQ@mail.gmail.com
2017-03-20 15:49:09 -04:00
Robert Haas
6977b8b7f4 Port single-page btree vacuum logic to hash indexes.
This is advantageous for hash indexes for the same reasons it's good
for btrees: it accelerates space recycling, reducing bloat.

Ashutosh Sharma, reviewed by Amit Kapila and by me.  A bit of
additional hacking by me.

Discussion: http://postgr.es/m/CAE9k0PkRSyzx8dOnokEpUi2A-RFZK72WN0h9DEMv_ut9q6bPRw@mail.gmail.com
2017-03-15 22:18:56 -04:00
Robert Haas
f7b711c8bc Cosmetic fixes for hash index write-ahead logging.
Amit Kapila.  One of these was reported by Tom Lane.

Discussion: http://postgr.es/m/5515.1489514099@sss.pgh.pa.us
2017-03-15 07:22:49 -04:00
Robert Haas
bb4a39637a hash: Support WAL consistency checking.
Kuntal Ghosh, reviewed by Amit Kapila and Ashutosh Sharma, with
a few tweaks by me.

Discussion: http://postgr.es/m/CAGz5QCJLERUn_zoO0eDv6_Y_d0o4tNTMPeR7ivTLBg4rUrJdwg@mail.gmail.com
2017-03-14 14:58:56 -04:00
Robert Haas
c11453ce0a hash: Add write-ahead logging support.
The warning about hash indexes not being write-ahead logged and their
use being discouraged has been removed.  "snapshot too old" is now
supported for tables with hash indexes.  Most importantly, barring
bugs, hash indexes will now be crash-safe and usable on standbys.

This commit doesn't yet add WAL consistency checking for hash
indexes, as we now have for other index types; a separate patch has
been submitted to cure that lack.

Amit Kapila, reviewed and slightly modified by me.  The larger patch
series of which this is a part has been reviewed and tested by Álvaro
Herrera, Ashutosh Sharma, Mark Kirkwood, Jeff Janes, and Jesper
Pedersen.

Discussion: http://postgr.es/m/CAA4eK1JOBX=YU33631Qh-XivYXtPSALh514+jR8XeD7v+K3r_Q@mail.gmail.com
2017-03-14 13:27:02 -04:00
Robert Haas
38305398cd hash: Refactor hash index creation.
The primary goal here is to move all of the related page modifications
to a single section of code, in preparation for adding write-ahead
logging.  In passing, rename _hash_metapinit to _hash_init, since it
initializes more than just the metapage.

Amit Kapila.  The larger patch series of which this is a part has been
reviewed and tested by Álvaro Herrera, Ashutosh Sharma, Mark Kirkwood,
Jeff Janes, and Jesper Pedersen.
2017-03-07 17:03:51 -05:00
Robert Haas
21a3cf4128 hash: Refactor and clean up bucket split code.
As with commit 30df93f698 and commit
b0f18cb77f, the goal here is to move all
of the related page modifications to a single section of code, in
preparation for adding write-ahead logging.

Amit Kapila, with slight changes by me.  The larger patch series of
which this is a part has been reviewed and tested by Álvaro Herrera,
Ashutosh Sharma, Mark Kirkwood, Jeff Janes, and Jesper Pedersen.
2017-03-01 14:43:38 +05:30
Robert Haas
30df93f698 hash: Refactor overflow page allocation.
As with commit b0f18cb77f, the goal
here is to move all of the related page modifications to a single
section of code, in preparation for adding write-ahead logging.

Amit Kapila, with slight changes by me.  The larger patch series
of which this is a part has been reviewed and tested by Álvaro
Herrera, Ashutosh Sharma, Mark Kirkwood, Jeff Janes, and Jesper
Pedersen, all of whom should also have been credited in the
previous commit message.
2017-02-27 22:59:55 +05:30
Robert Haas
b0f18cb77f hash: Refactor bucket squeeze code.
In preparation for adding write-ahead logging to hash indexes,
refactor _hash_freeovflpage and _hash_squeezebucket so that all
related page modifications happen in a single section of code.  The
previous coding assumed that it would be fine to move tuples one at a
time, and also that the various operations involved in freeing an
overflow page didn't necessarily all need to be done together, all
of which is true if you don't care about write-ahead logging.

Amit Kapila, with slight changes by me.
2017-02-27 22:34:21 +05:30
Robert Haas
5262f7a4fc Add optimizer and executor support for parallel index scans.
In combination with 569174f1be, which
taught the btree AM how to perform parallel index scans, this allows
parallel index scan plans on btree indexes.  This infrastructure
should be general enough to support parallel index scans for other
index AMs as well, if someone updates them to support parallel
scans.

Amit Kapila, reviewed and tested by Anastasia Lubennikova, Tushar
Ahuja, and Haribabu Kommi, and me.
2017-02-15 13:53:24 -05:00
Robert Haas
fc8219dc54 pageinspect: Fix hash_bitmap_info not to read the underlying page.
It did that to verify that the page was an overflow page rather than
anything else, but that means that checking the status of all the
overflow bits requires reading the entire index.  So don't do that.
The new code validates that the page is not a primary bucket page
or bitmap page by looking at the metapage, so that using this on
large numbers of pages can be reasonably efficient.

Ashutosh Sharma, per a complaint from me, and with further
modifications by me.
2017-02-09 14:34:34 -05:00
Tom Lane
86d911ec0f Allow index AMs to cache data across aminsert calls within a SQL command.
It's always been possible for index AMs to cache data across successive
amgettuple calls within a single SQL command: the IndexScanDesc.opaque
field is meant for precisely that.  However, no comparable facility
exists for amortizing setup work across successive aminsert calls.
This patch adds such a feature and teaches GIN, GIST, and BRIN to use it
to amortize catalog lookups they'd previously been doing on every call.
(The other standard index AMs keep everything they need in the relcache,
so there's little to improve there.)

For GIN, the overall improvement in a statement that inserts many rows
can be as much as 10%, though it seems a bit less for the other two.
In addition, this makes a really significant difference in runtime
for CLOBBER_CACHE_ALWAYS tests, since in those builds the repeated
catalog lookups are vastly more expensive.

The reason this has been hard up to now is that the aminsert function is
not passed any useful place to cache per-statement data.  What I chose to
do is to add suitable fields to struct IndexInfo and pass that to aminsert.
That's not widening the index AM API very much because IndexInfo is already
within the ken of ambuild; in fact, by passing the same info to aminsert
as to ambuild, this is really removing an inconsistency in the AM API.

Discussion: https://postgr.es/m/27568.1486508680@sss.pgh.pa.us
2017-02-09 11:52:12 -05:00
Robert Haas
94708c0e8c Fix compiler warning.
Mithun Cy, per a report by Erik Rijkers
2017-02-07 15:09:14 -05:00
Robert Haas
293e24e507 Cache hash index's metapage in rel->rd_amcache.
This avoids a very significant amount of buffer manager traffic and
contention when scanning hash indexes, because it's no longer
necessary to lock and pin the metapage for every scan.  We do need
some way of figuring out when the cache is too stale to use any more,
so that when we lock the primary bucket page to which the cached
metapage points us, we can tell whether a split has occurred since we
cached the metapage data.  To do that, we use the hash_prevblkno field
in the primary bucket page, which would otherwise always be set to
InvalidBuffer.

This patch contains code so that it will continue working (although
less efficiently) with hash indexes built before this change, but
perhaps we should consider bumping the hash version and ripping out
the compatibility code.  That decision can be made later, though.

Mithun Cy, reviewed by Jesper Pedersen, Amit Kapila, and by me.
Before committing, I made a number of cosmetic changes to the last
posted version of the patch, adjusted _hash_getcachedmetap to be more
careful about order of operation, and made some necessary updates to
the pageinspect documentation and regression tests.
2017-02-07 12:35:45 -05:00
Heikki Linnakangas
181bdb90ba Fix typos in comments.
Backpatch to all supported versions, where applicable, to make backpatching
of future fixes go more smoothly.

Josh Soref

Discussion: https://www.postgresql.org/message-id/CACZqfqCf+5qRztLPgmmosr-B0Ye4srWzzw_mo4c_8_B_mtjmJQ@mail.gmail.com
2017-02-06 11:33:58 +02:00
Robert Haas
08bf6e5295 pageinspect: Support hash indexes.
Patch by Jesper Pedersen and Ashutosh Sharma, with some error handling
improvements by me.  Tests from Peter Eisentraut.  Reviewed by Álvaro
Herrera, Michael Paquier, Jesper Pedersen, Jeff Janes, Peter
Eisentraut, Amit Kapila, Mithun Cy, and me.

Discussion: http://postgr.es/m/e2ac6c58-b93f-9dd9-f4e6-d6d30add7fdf@redhat.com
2017-02-02 14:19:32 -05:00
Robert Haas
7b4ac19982 Extend index AM API for parallel index scans.
This patch doesn't actually make any index AM parallel-aware, but it
provides the necessary functions at the AM layer to do so.

Rahila Syed, Amit Kapila, Robert Haas
2017-01-24 16:42:58 -05:00
Peter Eisentraut
f21a563d25 Move some things from builtins.h to new header files
This avoids that builtins.h has to include additional header files.
2017-01-20 20:29:53 -05:00