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198 Commits

Author SHA1 Message Date
d9d873bac6 Clean up some inconsistencies with GUC declarations
This is similar to 7d25958, and this commit takes care of all the
remaining inconsistencies between the initial value used in the C
variable associated to a GUC and its default value stored in the GUC
tables (as of pg_settings.boot_val).

Some of the initial values of the GUCs updated rely on a compile-time
default.  These are refactored so as the GUC table and its C declaration
use the same values.  This makes everything consistent with other
places, backend_flush_after, bgwriter_flush_after, port,
checkpoint_flush_after doing so already, for example.

Extracted from a larger patch by Peter Smith.  The spots updated in the
modules are from me.

Author: Peter Smith, Michael Paquier
Reviewed-by: Nathan Bossart, Tom Lane, Justin Pryzby
Discussion: https://postgr.es/m/CAHut+PtHE0XSfjjRQ6D4v7+dqzCw=d+1a64ujra4EX8aoc_Z+w@mail.gmail.com
2022-10-31 12:44:48 +09:00
b1099eca8f Remove AssertArg and AssertState
These don't offer anything over plain Assert, and their usage had
already been declared obsolescent.

Author: Nathan Bossart <nathandbossart@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://www.postgresql.org/message-id/20221009210148.GA900071@nathanxps13
2022-10-28 09:19:06 +02:00
a601366a46 Harmonize more parameter names in bulk.
Make sure that function declarations use names that exactly match the
corresponding names from function definitions in optimizer, parser,
utility, libpq, and "commands" code, as well as in remaining library
code.  Do the same for all code related to frontend programs (with the
exception of pg_dump/pg_dumpall related code).

Like other recent commits that cleaned up function parameter names, this
commit was written with help from clang-tidy.  Later commits will handle
ecpg and pg_dump/pg_dumpall.

Author: Peter Geoghegan <pg@bowt.ie>
Reviewed-By: David Rowley <dgrowleyml@gmail.com>
Discussion: https://postgr.es/m/CAH2-WznJt9CMM9KJTMjJh_zbL5hD9oX44qdJ4aqZtjFi-zA3Tg@mail.gmail.com
2022-09-20 13:09:30 -07:00
6bcda4a721 Fix incorrect uses of Datum conversion macros
Since these macros just cast whatever you give them to the designated
output type, and many normal uses also cast the output type further, a
number of incorrect uses go undiscovered.  The fixes in this patch
have been discovered by changing these macros to inline functions,
which is the subject of a future patch.

Reviewed-by: Aleksander Alekseev <aleksander@timescale.com>
Discussion: https://www.postgresql.org/message-id/flat/8528fb7e-0aa2-6b54-85fb-0c0886dbd6ed%40enterprisedb.com
2022-09-05 13:30:44 +02:00
d746021de1 Add construct_array_builtin, deconstruct_array_builtin
There were many calls to construct_array() and deconstruct_array() for
built-in types, for example, when dealing with system catalog columns.
These all hardcoded the type attributes necessary to pass to these
functions.

To simplify this a bit, add construct_array_builtin(),
deconstruct_array_builtin() as wrappers that centralize this hardcoded
knowledge.  This simplifies many call sites and reduces the amount of
hardcoded stuff that is spread around.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/2914356f-9e5f-8c59-2995-5997fc48bcba%40enterprisedb.com
2022-07-01 11:23:15 +02:00
708007dced Remove error message hints mentioning configure options
These are usually not useful since users will use packaged
distributions and won't be interested in rebuilding their installation
from source.  Also, we have only used these kinds of hints for some
features and in some places, not consistently throughout.

Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/2552aed7-d0e9-280a-54aa-2dc7073f371d%40enterprisedb.com
2022-04-08 07:41:55 +02:00
068739fb4f Fix incorrect xmlschema output for types timetz and timestamptz.
The output of table_to_xmlschema() and allied functions includes
a regex describing valid values for these types ... but the regex
was itself invalid, as it failed to escape a literal "+" sign.

Report and fix by Renan Soares Lopes.  Back-patch to all
supported branches.

Discussion: https://postgr.es/m/7f6fabaa-3f8f-49ab-89ca-59fbfe633105@me.com
2022-03-18 16:01:42 -04:00
27b77ecf9f Update copyright for 2022
Backpatch-through: 10
2022-01-07 19:04:57 -05:00
f9ea296031 Make use of PG_INT64_MAX/PG_INT64_MIN
This code was written before those symbols were introduced, but now we
can simplify it.
2021-09-22 07:31:05 +02:00
ae03a7c739 Remove some unnecessary casts in format arguments
We can use %zd or %zu directly, no need to cast to int.  Conversely,
some code was casting away from int when it could be using %d
directly.
2021-08-08 22:08:07 +02:00
ec6e70c79f Refactor some error messages for easier translation 2021-05-12 07:42:51 +02:00
b49154b3b7 Simplify some comments in xml.c
Author: Justin Pryzby
Discussion: https://postgr.es/m/X/Ff7jfnvJUab013@paquier.xyz
2021-01-04 19:47:58 +09:00
ca3b37487b Update copyright for 2021
Backpatch-through: 9.5
2021-01-02 13:06:25 -05:00
a6525588b7 Allow Unicode escapes in any server encoding, not only UTF-8.
SQL includes provisions for numeric Unicode escapes in string
literals and identifiers.  Previously we only accepted those
if they represented ASCII characters or the server encoding
was UTF-8, making the conversion to internal form trivial.
This patch adjusts things so that we'll call the appropriate
encoding conversion function in less-trivial cases, allowing
the escape sequence to be accepted so long as it corresponds
to some character available in the server encoding.

This also applies to processing of Unicode escapes in JSONB.
However, the old restriction still applies to client-side
JSON processing, since that hasn't got access to the server's
encoding conversion infrastructure.

This patch includes some lexer infrastructure that simplifies
throwing errors with error cursors pointing into the middle of
a string (or other complex token).  For the moment I only used
it for errors relating to Unicode escapes, but we might later
expand the usage to some other cases.

Patch by me, reviewed by John Naylor.

Discussion: https://postgr.es/m/2393.1578958316@sss.pgh.pa.us
2020-03-06 14:17:43 -05:00
3ed2005ff5 Introduce macros for typalign and typstorage constants.
Our usual practice for "poor man's enum" catalog columns is to define
macros for the possible values and use those, not literal constants,
in C code.  But for some reason lost in the mists of time, this was
never done for typalign/attalign or typstorage/attstorage.  It's never
too late to make it better though, so let's do that.

The reason I got interested in this right now is the need to duplicate
some uses of the TYPSTORAGE constants in an upcoming ALTER TYPE patch.
But in general, this sort of change aids greppability and readability,
so it's a good idea even without any specific motivation.

I may have missed a few places that could be converted, and it's even
more likely that pending patches will re-introduce some hard-coded
references.  But that's not fatal --- there's no expectation that
we'd actually change any of these values.  We can clean up stragglers
over time.

Discussion: https://postgr.es/m/16457.1583189537@sss.pgh.pa.us
2020-03-04 10:34:25 -05:00
7559d8ebfa Update copyrights for 2020
Backpatch-through: update all files in master, backpatch legal files through 9.4
2020-01-01 12:21:45 -05:00
581a55889b Fix nested error handling in PG_FINALLY
We need to pop the error stack before running the user-supplied
PG_FINALLY code.  Otherwise an error in the cleanup code would end up
at the same sigsetjmp() invocation and result in an infinite error
handling loop.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/95a822c3-728b-af0e-d7e5-71890507ae0c%402ndquadrant.com
2019-11-07 09:56:47 +01:00
3feb6ace7c Check after errors of SPI_execute() in xml.c
SPI gets used to build a list of relation OIDs for XML object
generation, and one code path building a list uses SPI_execute() without
looking at errors it produces.  So fix that.

Author: Mark Dilger
Reviewed-by: Michael Paquier, Pavel Stehule
Discussion: https://postgr.es/m/17d30445-4862-7917-170f-84328dcd292d@gmail.com
2019-11-07 11:13:31 +09:00
a63c84e59a Fix some compiler warnings on older compilers
Some older compilers appear to not understand the recently introduced
PG_FINALLY code structure that well in some circumstances and complain
about possibly uninitialized variables.  So to fix, initialize the
variables explicitly in the cases complained about.

Discussion: https://www.postgresql.org/message-id/flat/95a822c3-728b-af0e-d7e5-71890507ae0c%402ndquadrant.com
2019-11-04 11:07:32 +01:00
604bd36711 PG_FINALLY
This gives an alternative way of catching exceptions, for the common
case where the cleanup code is the same in the error and non-error
cases.  So instead of

    PG_TRY();
    {
        ... code that might throw ereport(ERROR) ...
    }
    PG_CATCH();
    {
        cleanup();
	PG_RE_THROW();
    }
    PG_END_TRY();
    cleanup();

one can write

    PG_TRY();
    {
        ... code that might throw ereport(ERROR) ...
    }
    PG_FINALLY();
    {
        cleanup();
    }
    PG_END_TRY();

Discussion: https://www.postgresql.org/message-id/flat/95a822c3-728b-af0e-d7e5-71890507ae0c%402ndquadrant.com
2019-11-01 11:18:03 +01:00
66bde49d96 Fix inconsistencies and typos in the tree, take 10
This addresses some issues with unnecessary code comments, fixes various
typos in docs and comments, and removes some orphaned structures and
definitions.

Author: Alexander Lakhin
Discussion: https://postgr.es/m/9aabc775-5494-b372-8bcb-4dfc0bd37c68@gmail.com
2019-08-13 13:53:41 +09:00
1e6a759838 Use appendBinaryStringInfo in more places where the length is known
When we already know the length that we're going to append, then it
makes sense to use appendBinaryStringInfo instead of
appendStringInfoString so that the append can be performed with a simple
memcpy() using a known length rather than having to first perform a
strlen() call to obtain the length.

Discussion: https://postgr.es/m/CAKJS1f8+FRAM1s5+mAa3isajeEoAaicJ=4e0WzrH3tAusbbiMQ@mail.gmail.com
2019-07-23 00:14:11 +12:00
8255c7a5ee Phase 2 pgindent run for v12.
Switch to 2.1 version of pg_bsd_indent.  This formats
multiline function declarations "correctly", that is with
additional lines of parameter declarations indented to match
where the first line's left parenthesis is.

Discussion: https://postgr.es/m/CAEepm=0P3FeTXRcU5B2W3jv3PgRVZ-kGUXLGfd42FFhUROO3ug@mail.gmail.com
2019-05-22 13:04:48 -04:00
c06e3550dc Don't request pretty-printed output from xmlNodeDump().
xml.c passed format = 1 to xmlNodeDump(), resulting in sometimes getting
extra whitespace (newlines + spaces) in the output.  We don't really want
that, first because whitespace might be semantically significant in some
XML uses, and second because it happens only very inconsistently.  Only
one case in our regression tests is affected.

This potentially affects the results of xpath() and the XMLTABLE construct,
when emitting nodeset values.

Note that the older code in contrib/xml2 doesn't do this; it seems
to have been an aboriginal bad decision in commit ea3b212fe.

While this definitely seems like a bug to me, the small number of
complaints to date argues against back-patching a behavioral change.
Hence, fix in HEAD only, at least for now.

Per report from Jean-Marc Voillequin.

Discussion: https://postgr.es/m/1EC8157EB499BF459A516ADCF135ADCE3A23A9CA@LON-WGMSX712.ad.moodys.net
2019-04-23 10:51:07 -04:00
b2b819019f Add volatile qualifier missed in commit 2e616dee9.
Noted by Pavel Stehule

Discussion: https://postgr.es/m/CAFj8pRAaGO5FX7bnP3E=mRssoK8y5T78x7jKy-vDiyS68L888Q@mail.gmail.com
2019-04-01 14:37:25 -04:00
f778e537a0 Remove inadequate check for duplicate "xml" PI.
I failed to think about PIs starting with "xml".  We don't really
need this check at all, so just take it out.  Oversight in
commit 8d1dadb25 et al.
2019-03-23 17:40:19 -04:00
8d1dadb25b Accept XML documents when xmloption = content, as required by SQL:2006+.
Previously we were using the SQL:2003 definition, which doesn't allow
this, but that creates a serious dump/restore gotcha: there is no
setting of xmloption that will allow all valid XML data.  Hence,
switch to the 2006 definition.

Since libxml doesn't accept <!DOCTYPE> directives in the mode we
use for CONTENT parsing, the implementation is to detect <!DOCTYPE>
in the input and switch to DOCUMENT parsing mode.  This should not
cost much, because <!DOCTYPE> should be close to the front of the
input if it's there at all.  It's possible that this causes the
error messages for malformed input to be slightly different than
they were before, if said input includes <!DOCTYPE>; but that does
not seem like a big problem.

In passing, buy back a few cycles in parsing of large XML documents
by not doing strlen() of the whole input in parse_xml_decl().

Back-patch because dump/restore failures are not nice.  This change
shouldn't break any cases that worked before, so it seems safe to
back-patch.

Chapman Flack (revised a bit by me)

Discussion: https://postgr.es/m/CAN-V+g-6JqUQEQZ55Q3toXEN6d5Ez5uvzL4VR+8KtvJKj31taw@mail.gmail.com
2019-03-23 16:51:37 -04:00
2e616dee9e Fix crash with old libxml2
Certain libxml2 versions (such as the 2.7.6 commonly seen in older
distributions, but apparently only on x86_64) contain a bug that causes
xmlCopyNode, when called on a XML_DOCUMENT_NODE, to return a node that
xmlFreeNode crashes on.  Arrange to call xmlFreeDoc instead of
xmlFreeNode for those nodes.

Per buildfarm members lapwing and grison.

Author: Pavel Stehule, light editing by Álvaro.
Discussion: https://postgr.es/m/20190308024436.GA2374@alvherre.pgsql
2019-03-08 19:13:25 -03:00
251cf2e27b Fix minor deficiencies in XMLTABLE, xpath(), xmlexists()
Correctly process nodes of more types than previously.  In some cases,
nodes were being ignored (nothing was output); in other cases, trying to
return them resulted in errors about unrecognized nodes.  In yet other
cases, necessary escaping (of XML special characters) was not being
done.  Fix all those (as far as the authors could find) and add
regression tests cases verifying the new behavior.

I (Álvaro) was of two minds about backpatching these changes.  They do
seem bugfixes that would benefit most users of the affected functions;
but on the other hand it would change established behavior in minor
releases, so it seems prudent not to.

Authors: Pavel Stehule, Markus Winand, Chapman Flack
Discussion:
   https://postgr.es/m/CAFj8pRA6J25CtAZ2TuRvxK3gat7-bBUYh0rfE2yM7Hj9GD14Dg@mail.gmail.com
   https://postgr.es/m/8BDB0627-2105-4564-AA76-7849F028B96E@winand.at

The elephant in the room as pointed out by Chapman Flack, not fixed in
this commit, is that we still have XMLTABLE operating on XPath 1.0
instead of the standard-mandated XQuery (or even its subset XPath 2.0).
Fixing that is a major undertaking, however.
2019-03-07 18:16:34 -03:00
0edef16d76 Defend against null error message reported by libxml2.
While this isn't really supposed to happen, it can occur in OOM
situations and perhaps others.  Instead of crashing, substitute
"(no message provided)".

I didn't worry about localizing this text, since we aren't
localizing anything else here; besides, if we're on the edge of
OOM, it's unlikely gettext() would work.

Report and fix by Sergio Conde Gómez in bug #15624.

Discussion: https://postgr.es/m/15624-4dea54091a2864e6@postgresql.org
2019-02-08 13:30:42 -05:00
e0c4ec0728 Replace uses of heap_open et al with the corresponding table_* function.
Author: Andres Freund
Discussion: https://postgr.es/m/20190111000539.xbv7s6w7ilcvm7dp@alap3.anarazel.de
2019-01-21 10:51:37 -08:00
111944c5ee Replace heapam.h includes with {table, relation}.h where applicable.
A lot of files only included heapam.h for relation_open, heap_open etc
- replace the heapam.h include in those files with the narrower
header.

Author: Andres Freund
Discussion: https://postgr.es/m/20190111000539.xbv7s6w7ilcvm7dp@alap3.anarazel.de
2019-01-21 10:51:37 -08:00
4c850ecec6 Don't include heapam.h from others headers.
heapam.h previously was included in a number of widely used
headers (e.g. execnodes.h, indirectly in executor.h, ...). That's
problematic on its own, as heapam.h contains a lot of low-level
details that don't need to be exposed that widely, but becomes more
problematic with the upcoming introduction of pluggable table storage
- it seems inappropriate for heapam.h to be included that widely
afterwards.

heapam.h was largely only included in other headers to get the
HeapScanDesc typedef (which was defined in heapam.h, even though
HeapScanDescData is defined in relscan.h). The better solution here
seems to be to just use the underlying struct (forward declared where
necessary). Similar for BulkInsertState.

Another problem was that LockTupleMode was used in executor.h - parts
of the file tried to cope without heapam.h, but due to the fact that
it indirectly included it, several subsequent violations of that goal
were not not noticed. We could just reuse the approach of declaring
parameters as int, but it seems nicer to move LockTupleMode to
lockoptions.h - that's not a perfect location, but also doesn't seem
bad.

As a number of files relied on implicitly included heapam.h, a
significant number of files grew an explicit include. It's quite
probably that a few external projects will need to do the same.

Author: Andres Freund
Reviewed-By: Alvaro Herrera
Discussion: https://postgr.es/m/20190114000701.y4ttcb74jpskkcfb@alap3.anarazel.de
2019-01-14 16:24:41 -08:00
97c39498e5 Update copyright for 2019
Backpatch-through: certain files through 9.4
2019-01-02 12:44:25 -05:00
e474c2b7e4 Set correct context for XPath evaluation
According to the SQL standard, the context of XMLTABLE's XPath
row_expression is the document node of the XML input document, not the
root node.  This becomes visible when a relative path rather than
absolute is used as row expression.  Absolute paths is what was used in
original tests and docs (and the most common form used in examples
throughout the interwebs), which explains why this wasn't noticed
before.

Other functions such as xpath() and xpath_exists() also have this
problem.  While not specified by the SQL standard, it would be pretty
odd to leave those functions to behave differently than XMLTABLE, so
change them too.  However, this is a backwards-incompatible change.

No backpatch, out of fear of breaking code depending on the original
broken behavior.

Author: Markus Winand
Reported-By: Markus Winand
Reviewed-by: Álvaro Herrera
Discussion: https://postgr.es/m/0684A598-002C-42A2-AE12-F024A324EAE4@winand.at
2018-06-21 15:56:11 -04:00
b7f0be9a7e Accept TEXT and CDATA nodes in XMLTABLE's column_expression.
Column expressions that match TEXT or CDATA nodes must return the
contents of the nodes themselves, not the content of non-existing
children (i.e. the empty string).

Author: Markus Winand
Reported-by: Markus Winand
Reviewed-by: Álvaro Herrera
Discussion: https://postgr.es/m/0684A598-002C-42A2-AE12-F024A324EAE4@winand.at
2018-06-20 12:58:12 -04:00
9d4649ca49 Update copyright for 2018
Backpatch-through: certain files through 9.3
2018-01-02 23:30:12 -05:00
2918fcedbf Ignore XML declaration in xpath_internal(), for UTF8 databases.
When a value contained an XML declaration naming some other encoding,
this function interpreted UTF8 bytes as the named encoding, yielding
mojibake.  xml_parse() already has similar logic.  This would be
necessary but not sufficient for non-UTF8 databases, so preserve
behavior there until the xpath facility can support such databases
comprehensively.  Back-patch to 9.3 (all supported versions).

Pavel Stehule and Noah Misch

Discussion: https://postgr.es/m/CAFj8pRC-dM=tT=QkGi+Achkm+gwPmjyOayGuUfXVumCxkDgYWg@mail.gmail.com
2017-11-11 11:10:53 -08:00
0e1539ba0d Add some const decorations to prototypes
Reviewed-by: Fabien COELHO <coelho@cri.ensmp.fr>
2017-11-10 13:38:57 -05:00
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
2cd7084524 Change tupledesc->attrs[n] to TupleDescAttr(tupledesc, n).
This is a mechanical change in preparation for a later commit that
will change the layout of TupleDesc.  Introducing a macro to abstract
the details of where attributes are stored will allow us to change
that in separate step and revise it in future.

Author: Thomas Munro, editorialized by Andres Freund
Reviewed-By: Andres Freund
Discussion: https://postgr.es/m/CAEepm=0ZtQ-SpsgCyzzYpsXS6e=kZWqk3g5Ygn3MDV7A8dabUA@mail.gmail.com
2017-08-20 11:19:07 -07:00
77d05706be Fix up some misusage of appendStringInfo() and friends
Change to appendStringInfoChar() or appendStringInfoString() where those
can be used.

Author: David Rowley <david.rowley@2ndquadrant.com>
Reviewed-by: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
2017-08-15 23:34:39 -04:00
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
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
a6fd7b7a5f Post-PG 10 beta1 pgindent run
perltidy run not included.
2017-05-17 16:31:56 -04:00
0de791ed76 Fix cursor_to_xml in tableforest false mode
It only produced <row> elements but no wrapping <table> element.

By contrast, cursor_to_xmlschema produced a schema that is now correct
but did not previously match the XML data produced by cursor_to_xml.

In passing, also fix a minor misunderstanding about moving cursors in
the tests related to this.

Reported-by: filip@jirsak.org
Based-on-patch-by: Thomas Munro <thomas.munro@enterprisedb.com>
2017-05-03 21:41:10 -04:00
b8d7f053c5 Faster expression evaluation and targetlist projection.
This replaces the old, recursive tree-walk based evaluation, with
non-recursive, opcode dispatch based, expression evaluation.
Projection is now implemented as part of expression evaluation.

This both leads to significant performance improvements, and makes
future just-in-time compilation of expressions easier.

The speed gains primarily come from:
- non-recursive implementation reduces stack usage / overhead
- simple sub-expressions are implemented with a single jump, without
  function calls
- sharing some state between different sub-expressions
- reduced amount of indirect/hard to predict memory accesses by laying
  out operation metadata sequentially; including the avoidance of
  nearly all of the previously used linked lists
- more code has been moved to expression initialization, avoiding
  constant re-checks at evaluation time

Future just-in-time compilation (JIT) has become easier, as
demonstrated by released patches intended to be merged in a later
release, for primarily two reasons: Firstly, due to a stricter split
between expression initialization and evaluation, less code has to be
handled by the JIT. Secondly, due to the non-recursive nature of the
generated "instructions", less performance-critical code-paths can
easily be shared between interpreted and compiled evaluation.

The new framework allows for significant future optimizations. E.g.:
- basic infrastructure for to later reduce the per executor-startup
  overhead of expression evaluation, by caching state in prepared
  statements.  That'd be helpful in OLTPish scenarios where
  initialization overhead is measurable.
- optimizing the generated "code". A number of proposals for potential
  work has already been made.
- optimizing the interpreter. Similarly a number of proposals have
  been made here too.

The move of logic into the expression initialization step leads to some
backward-incompatible changes:
- Function permission checks are now done during expression
  initialization, whereas previously they were done during
  execution. In edge cases this can lead to errors being raised that
  previously wouldn't have been, e.g. a NULL array being coerced to a
  different array type previously didn't perform checks.
- The set of domain constraints to be checked, is now evaluated once
  during expression initialization, previously it was re-built
  every time a domain check was evaluated. For normal queries this
  doesn't change much, but e.g. for plpgsql functions, which caches
  ExprStates, the old set could stick around longer.  The behavior
  around might still change.

Author: Andres Freund, with significant changes by Tom Lane,
	changes by Heikki Linnakangas
Reviewed-By: Tom Lane, Heikki Linnakangas
Discussion: https://postgr.es/m/20161206034955.bh33paeralxbtluv@alap3.anarazel.de
2017-03-25 14:52:06 -07:00
3a0d473192 Use wrappers of PG_DETOAST_DATUM_PACKED() more.
This makes almost all core code follow the policy introduced in the
previous commit.  Specific decisions:

- Text search support functions with char* and length arguments, such as
  prsstart and lexize, may receive unaligned strings.  I doubt
  maintainers of non-core text search code will notice.

- Use plain VARDATA() on values detoasted or synthesized earlier in the
  same function.  Use VARDATA_ANY() on varlenas sourced outside the
  function, even if they happen to always have four-byte headers.  As an
  exception, retain the universal practice of using VARDATA() on return
  values of SendFunctionCall().

- Retain PG_GETARG_BYTEA_P() in pageinspect.  (Page images are too large
  for a one-byte header, so this misses no optimization.)  Sites that do
  not call get_page_from_raw() typically need the four-byte alignment.

- For now, do not change btree_gist.  Its use of four-byte headers in
  memory is partly entangled with storage of 4-byte headers inside
  GBT_VARKEY, on disk.

- For now, do not change gtrgm_consistent() or gtrgm_distance().  They
  incorporate the varlena header into a cache, and there are multiple
  credible implementation strategies to consider.
2017-03-12 19:35:34 -04:00
9c2635e26f Fix hard-coded relkind constants in assorted other files.
Although it's reasonable to expect that most of these constants will
never change, that does not make it good programming style to hard-code
the value rather than using the RELKIND_FOO macros.

I think I've now gotten all the hard-coded references in C code.
Unfortunately there's no equally convenient way to parameterize
SQL files ...

Discussion: https://postgr.es/m/11145.1488931324@sss.pgh.pa.us
2017-03-09 23:36:52 -05:00
f379121093 Suppress compiler warning in non-USE_LIBXML builds.
Compilers that don't realize that ereport(ERROR) doesn't return
complained that XmlTableGetValue() failed to return a value.

Also, make XmlTableFetchRow's non-USE_LIBXML case look more like
the other ones.  As coded, it could lead to "unreachable code"
warnings with USE_LIBXML enabled.

Oversights in commit fcec6caaf.  Per buildfarm.
2017-03-08 16:10:00 -05:00