| Commit message (Collapse) | Author | Age |
|---|
| ... | |
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
If we can't read the query texts file (whether because out-of-memory, or
for some other reason), give up and reset the file to empty, discarding all
stored query texts, though not the statistics per se. We used to leave
things alone and hope for better luck next time, but the problem is that
the file is only going to get bigger and even harder to slurp into memory.
Better to do something that will get us out of trouble.
Likewise reset the file to empty for any other failure within gc_qtexts().
The previous behavior after a write error was to discard query texts but
not do anything to truncate the file, which is just weird.
Also, increase the maximum supported file size from MaxAllocSize to
MaxAllocHugeSize; this makes it more likely we'll be able to do a garbage
collection successfully.
Also, fix recalculation of mean_query_len within entry_dealloc() to match
the calculation in gc_qtexts(). The previous coding overlooked the
possibility of dropped texts (query_len == -1) and would underestimate the
mean of the remaining entries in such cases, thus possibly causing excess
garbage collection cycles.
In passing, add some errdetail to the log entry that complains about
insufficient memory to read the query texts file, which after all was
Jim Nasby's original complaint.
Back-patch to 9.4 where the current handling of query texts was
introduced.
Peter Geoghegan, rather editorialized upon by me
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
The original implementation of TABLESAMPLE modeled the tablesample method
API on index access methods, which wasn't a good choice because, without
specialized DDL commands, there's no way to build an extension that can
implement a TSM. (Raw inserts into system catalogs are not an acceptable
thing to do, because we can't undo them during DROP EXTENSION, nor will
pg_upgrade behave sanely.) Instead adopt an API more like procedural
language handlers or foreign data wrappers, wherein the only SQL-level
support object needed is a single handler function identified by having
a special return type. This lets us get rid of the supporting catalog
altogether, so that no custom DDL support is needed for the feature.
Adjust the API so that it can support non-constant tablesample arguments
(the original coding assumed we could evaluate the argument expressions at
ExecInitSampleScan time, which is undesirable even if it weren't outright
unsafe), and discourage sampling methods from looking at invisible tuples.
Make sure that the BERNOULLI and SYSTEM methods are genuinely repeatable
within and across queries, as required by the SQL standard, and deal more
honestly with methods that can't support that requirement.
Make a full code-review pass over the tablesample additions, and fix
assorted bugs, omissions, infelicities, and cosmetic issues (such as
failure to put the added code stanzas in a consistent ordering).
Improve EXPLAIN's output of tablesample plans, too.
Back-patch to 9.5 so that we don't have to support the original API
in production.
|
| |
|
|
|
|
| |
The AIX 7.1 libm is static, and AIX postgres executables do not export
symbols acquired from libraries. Back-patch to 9.5, where commit
cfe12763c32437bc708a64ce88a90c7544f16185 added a sqrt() call.
|
| | |
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
| |
Defer lookup of opfamily and input type of a of a user specified opclass
until the optimizer selects among available unique indexes; and store
the opclass in the parse analyzed tree instead. The primary reason for
doing this is that for rule deparsing it's easier to use the opclass
than the previous representation.
While at it also rename a variable in the inference code to better fit
it's purpose.
This is separate from the actual fixes for deparsing to make review
easier.
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This SQL standard functionality allows to aggregate data by different
GROUP BY clauses at once. Each grouping set returns rows with columns
grouped by in other sets set to NULL.
This could previously be achieved by doing each grouping as a separate
query, conjoined by UNION ALLs. Besides being considerably more concise,
grouping sets will in many cases be faster, requiring only one scan over
the underlying data.
The current implementation of grouping sets only supports using sorting
for input. Individual sets that share a sort order are computed in one
pass. If there are sets that don't share a sort order, additional sort &
aggregation steps are performed. These additional passes are sourced by
the previous sort step; thus avoiding repeated scans of the source data.
The code is structured in a way that adding support for purely using
hash aggregation or a mix of hashing and sorting is possible. Sorting
was chosen to be supported first, as it is the most generic method of
implementation.
Instead of, as in an earlier versions of the patch, representing the
chain of sort and aggregation steps as full blown planner and executor
nodes, all but the first sort are performed inside the aggregation node
itself. This avoids the need to do some unusual gymnastics to handle
having to return aggregated and non-aggregated tuples from underlying
nodes, as well as having to shut down underlying nodes early to limit
memory usage. The optimizer still builds Sort/Agg node to describe each
phase, but they're not part of the plan tree, but instead additional
data for the aggregation node. They're a convenient and preexisting way
to describe aggregation and sorting. The first (and possibly only) sort
step is still performed as a separate execution step. That retains
similarity with existing group by plans, makes rescans fairly simple,
avoids very deep plans (leading to slow explains) and easily allows to
avoid the sorting step if the underlying data is sorted by other means.
A somewhat ugly side of this patch is having to deal with a grammar
ambiguity between the new CUBE keyword and the cube extension/functions
named cube (and rollup). To avoid breaking existing deployments of the
cube extension it has not been renamed, neither has cube been made a
reserved keyword. Instead precedence hacking is used to make GROUP BY
cube(..) refer to the CUBE grouping sets feature, and not the function
cube(). To actually group by a function cube(), unlikely as that might
be, the function name has to be quoted.
Needs a catversion bump because stored rules may change.
Author: Andrew Gierth and Atri Sharma, with contributions from Andres Freund
Reviewed-By: Andres Freund, Noah Misch, Tom Lane, Svenne Krap, Tomas
Vondra, Erik Rijkers, Marti Raudsepp, Pavel Stehule
Discussion: CAOeZVidmVRe2jU6aMk_5qkxnB7dfmPROzM7Ur8JPW5j8Y5X-Lw@mail.gmail.com
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
The newly added ON CONFLICT clause allows to specify an alternative to
raising a unique or exclusion constraint violation error when inserting.
ON CONFLICT refers to constraints that can either be specified using a
inference clause (by specifying the columns of a unique constraint) or
by naming a unique or exclusion constraint. DO NOTHING avoids the
constraint violation, without touching the pre-existing row. DO UPDATE
SET ... [WHERE ...] updates the pre-existing tuple, and has access to
both the tuple proposed for insertion and the existing tuple; the
optional WHERE clause can be used to prevent an update from being
executed. The UPDATE SET and WHERE clauses have access to the tuple
proposed for insertion using the "magic" EXCLUDED alias, and to the
pre-existing tuple using the table name or its alias.
This feature is often referred to as upsert.
This is implemented using a new infrastructure called "speculative
insertion". It is an optimistic variant of regular insertion that first
does a pre-check for existing tuples and then attempts an insert. If a
violating tuple was inserted concurrently, the speculatively inserted
tuple is deleted and a new attempt is made. If the pre-check finds a
matching tuple the alternative DO NOTHING or DO UPDATE action is taken.
If the insertion succeeds without detecting a conflict, the tuple is
deemed inserted.
To handle the possible ambiguity between the excluded alias and a table
named excluded, and for convenience with long relation names, INSERT
INTO now can alias its target table.
Bumps catversion as stored rules change.
Author: Peter Geoghegan, with significant contributions from Heikki
Linnakangas and Andres Freund. Testing infrastructure by Jeff Janes.
Reviewed-By: Heikki Linnakangas, Andres Freund, Robert Haas, Simon Riggs,
Dean Rasheed, Stephen Frost and many others.
|
| |
|
|
|
|
| |
We can use that macro as long as we put the value into a local variable.
Commit 735cd6128 was not wrong on its own terms, but I think this way
looks nicer, and it should save a few cycles on 32-bit machines.
|
| |
|
|
|
|
|
| |
The stddev calculation included a faster but unportable sqrt function.
This is not worth the extra effort, and won't work everywhere. If the
standard library function is good enough for the SQL function it
should be good enough here too.
|
| |
|
|
|
|
| |
Stddev is calculated on the fly, and the code in commit 717f70953264 was
using Float8GetDatumFast() inappropriately to convert the result to a
Datum. Mea culpa. It now uses Float8GetDatum().
|
| |
|
|
|
|
| |
The new fields are min_time, max_time, mean_time and stddev_time.
Based on an original patch from Mitsumasa KONDO, modified by me. Reviewed by Petr Jelínek.
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
contrib/pg_stat_statements will sometimes run the core lexer a second time
on submitted statements. Formerly, if you had standard_conforming_strings
turned off, this led to sometimes getting two copies of any warnings
enabled by escape_string_warning. While this is probably no longer a big
deal in the field, it's a pain for regression testing.
To fix, change the lexer so it doesn't consult the escape_string_warning
GUC variable directly, but looks at a copy in the core_yy_extra_type state
struct. Then, pg_stat_statements can change that copy to disable warnings
while it's redoing the lexing.
It seemed like a good idea to make this happen for all three of the GUCs
consulted by the lexer, not just escape_string_warning. There's not an
immediate use-case for callers to adjust the other two AFAIK, but making
it possible is easy enough and seems like good future-proofing.
Arguably this is a bug fix, but there doesn't seem to be enough interest to
justify a back-patch. We'd not be able to back-patch exactly as-is anyway,
for fear of breaking ABI compatibility of the struct. (We could perhaps
back-patch the addition of only escape_string_warning by adding it at the
end of the struct, where there's currently alignment padding space.)
|
| |
|
|
| |
Backpatch certain files through 9.0
|
| |
|
|
|
|
|
|
|
|
| |
Some of the many error messages introduced in 458857cc missed 'FROM
unpackaged'. Also e016b724 and 45ffeb7e forgot to quote extension
version numbers.
Backpatch to 9.1, just like 458857cc which introduced the messages. Do
so because the error messages thrown when the wrong command is copy &
pasted aren't easy to understand.
|
| |
|
|
|
|
|
|
|
|
| |
We also don't track PREPARE, nor do we track planning time in general, so
let's ignore DEALLOCATE as well for consistency.
Backpatch to 9.4, but not further than that. Although it seems unlikely that
anyone is relying on the current behavior, this is a behavioral change.
Fabien Coelho
|
| |
|
|
|
|
|
|
| |
Prominent binaries already had this metadata. A handful of minor
binaries, such as pg_regress.exe, still lack it; efforts to eliminate
such exceptions are welcome.
Michael Paquier, reviewed by MauMau.
|
| |
|
|
| |
Report by Robert Haas
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This SQL-standard feature allows a sub-SELECT yielding multiple columns
(but only one row) to be used to compute the new values of several columns
to be updated. While the same results can be had with an independent
sub-SELECT per column, such a workaround can require a great deal of
duplicated computation.
The standard actually says that the source for a multi-column assignment
could be any row-valued expression. The implementation used here is
tightly tied to our existing sub-SELECT support and can't handle other
cases; the Bison grammar would have some issues with them too. However,
I don't feel too bad about this since other cases can be converted into
sub-SELECTs. For instance, "SET (a,b,c) = row_valued_function(x)" could
be written "SET (a,b,c) = (SELECT * FROM row_valued_function(x))".
|
| |
|
|
|
|
|
|
|
|
|
|
|
| |
shutdown.
187492b6c2e8cafc5b39063ca3b67846e8155d24 changed pgstat.c so that
the stats files were saved into $PGDATA/pg_stat directory when the server
was shutdowned. But it accidentally forgot to change the location of
pg_stat_statements permanent stats file. This commit fixes pg_stat_statements
so that its stats file is also saved into $PGDATA/pg_stat at shutdown.
Since this fix changes the file layout, we don't back-patch it to 9.3
where this oversight was introduced.
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
On Mingw, it seems that scanf() doesn't necessarily accept the same format
codes that printf() does, and in particular it may fail to recognize %llu
even though printf() does. Since configure only probes printf() behavior
while setting up the INT64_FORMAT macros, this means it's unsafe to use
those macros with scanf(). We had only one instance of such a coding
pattern, in contrib/pg_stat_statements, so change that code to avoid
the problem.
Per buildfarm warnings. Back-patch to 9.0 where the troublesome code
was introduced.
Michael Paquier
|
| |
|
|
|
| |
This includes removing tabs after periods in C comments, which was
applied to back branches, so this change should not effect backpatching.
|
| |
|
|
|
|
|
|
| |
pgss_post_parse_analyze() neglected to pass the call on to any earlier
occupant of the post_parse_analyze_hook. There are no other users of that
hook in contrib/, and most likely none in the wild either, so this is
probably just a latent bug. But it's a bug nonetheless, so back-patch
to 9.2 where this code was introduced.
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Because of gcc -Wmissing-prototypes, all functions in dynamically
loadable modules must have a separate prototype declaration. This is
meant to detect global functions that are not declared in header files,
but in cases where the function is called via dfmgr, this is redundant.
Besides filling up space with boilerplate, this is a frequent source of
compiler warnings in extension modules.
We can fix that by creating the function prototype as part of the
PG_FUNCTION_INFO_V1 macro, which such modules have to use anyway. That
makes the code of modules cleaner, because there is one less place where
the entry points have to be listed, and creates an additional check that
functions have the right prototype.
Remove now redundant prototypes from contrib and other modules.
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
A large majority of the callers of pg_do_encoding_conversion were
specifying the database encoding as either source or target of the
conversion, meaning that we can use the less general functions
pg_any_to_server/pg_server_to_any instead.
The main advantage of using the latter functions is that they can make use
of a cached conversion-function lookup in the common case that the other
encoding is the current client_encoding. It's notationally cleaner too in
most cases, not least because of the historical artifact that the latter
functions use "char *" rather than "unsigned char *" in their APIs.
Note that pg_any_to_server will apply an encoding verification step in
some cases where pg_do_encoding_conversion would have just done nothing.
This seems to me to be a good idea at most of these call sites, though
it partially negates the performance benefit.
Per discussion of bug #9210.
|
| |
|
|
|
|
|
|
| |
The temporary statistics files don't need to be included in the backup
because they are always reset at the beginning of the archive recovery.
This patch changes pg_basebackup so that it skips all files located in
$PGDATA/pg_stat_tmp or the directory specified by stats_temp_directory
parameter.
|
| |
|
|
|
| |
generate_normalized_query() no longer needs to truncate text, but this
one comment didn't get the memo. Per Peter Geoghegan.
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This change allows us to eliminate the previous limit on stored query
length, and it makes the shared-memory hash table very much smaller,
allowing more statements to be tracked. (The default value of
pg_stat_statements.max is therefore increased from 1000 to 5000.)
In typical scenarios, the hash table can be large enough to hold all the
statements commonly issued by an application, so that there is little
"churn" in the set of tracked statements, and thus little need to do I/O
to the file.
To further reduce the need for I/O to the query-texts file, add a way
to retrieve all the columns of the pg_stat_statements view except for
the query text column. This is probably not of much interest for human
use but it could be exploited by programs, which will prefer using the
queryid anyway.
Ordinarily, we'd need to bump the extension version number for the latter
change. But since we already advanced pg_stat_statements' version number
from 1.1 to 1.2 in the 9.4 development cycle, it seems all right to just
redefine what 1.2 means.
Peter Geoghegan, reviewed by Pavel Stehule
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
| |
This makes it possible to store lwlocks as part of some other data
structure in the main shared memory segment, or in a dynamic shared
memory segment. There is still a main LWLock array and this patch does
not move anything out of it, but it provides necessary infrastructure
for doing that in the future.
This change is likely to increase the size of LWLockPadded on some
platforms, especially 32-bit platforms where it was previously only
16 bytes.
Patch by me. Review by Andres Freund and KaiGai Kohei.
|
| |
|
|
|
| |
Commit 91484409bdd17f330d10671d388b72d4ef1451d7 should have removed this
file, not just reduced it to zero size.
|
| |
|
|
|
| |
Update all files in head, and files COPYRIGHT and legal.sgml in all back
branches.
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This patch introduces generic support for ordered-set and hypothetical-set
aggregate functions, as well as implementations of the instances defined in
SQL:2008 (percentile_cont(), percentile_disc(), rank(), dense_rank(),
percent_rank(), cume_dist()). We also added mode() though it is not in the
spec, as well as versions of percentile_cont() and percentile_disc() that
can compute multiple percentile values in one pass over the data.
Unlike the original submission, this patch puts full control of the sorting
process in the hands of the aggregate's support functions. To allow the
support functions to find out how they're supposed to sort, a new API
function AggGetAggref() is added to nodeAgg.c. This allows retrieval of
the aggregate call's Aggref node, which may have other uses beyond the
immediate need. There is also support for ordered-set aggregates to
install cleanup callback functions, so that they can be sure that
infrastructure such as tuplesort objects gets cleaned up.
In passing, make some fixes in the recently-added support for variadic
aggregates, and make some editorial adjustments in the recent FILTER
additions for aggregates. Also, simplify use of IsBinaryCoercible() by
allowing it to succeed whenever the target type is ANY or ANYELEMENT.
It was inconsistent that it dealt with other polymorphic target types
but not these.
Atri Sharma and Andrew Gierth; reviewed by Pavel Stehule and Vik Fearing,
and rather heavily editorialized upon by Tom Lane
|
| |
|
|
| |
Peter Geoghegan
|
| |
|
|
|
|
|
| |
The query ID is the internal hash identifier of the statement,
and was not available in pg_stat_statements view so far.
Daniel Farina, Sameer Thakur and Peter Geoghegan, reviewed by me.
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This patch adds the ability to write TABLE( function1(), function2(), ...)
as a single FROM-clause entry. The result is the concatenation of the
first row from each function, followed by the second row from each
function, etc; with NULLs inserted if any function produces fewer rows than
others. This is believed to be a much more useful behavior than what
Postgres currently does with multiple SRFs in a SELECT list.
This syntax also provides a reasonable way to combine use of column
definition lists with WITH ORDINALITY: put the column definition list
inside TABLE(), where it's clear that it doesn't control the ordinality
column as well.
Also implement SQL-compliant multiple-argument UNNEST(), by turning
UNNEST(a,b,c) into TABLE(unnest(a), unnest(b), unnest(c)).
The SQL standard specifies TABLE() with only a single function, not
multiple functions, and it seems to require an implicit UNNEST() which is
not what this patch does. There may be something wrong with that reading
of the spec, though, because if it's right then the spec's TABLE() is just
a pointless alternative spelling of UNNEST(). After further review of
that, we might choose to adopt a different syntax for what this patch does,
but in any case this functionality seems clearly worthwhile.
Andrew Gierth, reviewed by Zoltán Böszörményi and Heikki Linnakangas, and
significantly revised by me
|
| | |
|
| |
|
|
|
|
|
|
|
| |
This is SQL-standard with a few extensions, namely support for
subqueries and outer references in clause expressions.
catversion bump due to change in Aggref and WindowFunc.
David Fetter, reviewed by Dean Rasheed.
|
| |
|
|
|
|
|
|
| |
Choose a saner ordering of parameters (adding a new input param after
the output params seemed a bit random), update the function's header
comment to match reality (cmon folks, is this really that hard?),
get rid of useless and sloppily-defined distinction between
PROCESS_UTILITY_SUBCOMMAND and PROCESS_UTILITY_GENERATED.
|
| |
|
|
|
| |
Fully update git head, and update back branches in ./COPYRIGHT and
legal.sgml files.
|
| |
|
|
| |
Per Peter Geoghegan.
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Commit 3855968f328918b6cd1401dd11d109d471a54d40 added syntax, pg_dump,
psql support, and documentation, but the triggers didn't actually fire.
With this commit, they now do. This is still a pretty basic facility
overall because event triggers do not get a whole lot of information
about what the user is trying to do unless you write them in C; and
there's still no option to fire them anywhere except at the very
beginning of the execution sequence, but it's better than nothing,
and a good building block for future work.
Along the way, add a regression test for ALTER LARGE OBJECT, since
testing of event triggers reveals that we haven't got one.
Dimitri Fontaine and Robert Haas
|
| |
|
|
| |
commit-fest.
|
| |
|
|
|
|
|
|
|
| |
Write the file to a temporary name and then rename() it into the
permanent name, to ensure it can't end up half-written and corrupt
in case of a crash during shutdown.
Unlink the file after it has been read so it's removed from the data
directory and not included in base backups going to replication slaves.
|
| |
|
|
|
| |
This seems more consistent with the pre-existing choices for names of
other statistics columns. Rename assorted internal identifiers to match.
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
| |
Display total time and I/O timings in milliseconds, for consistency with
the units used for timings in the core statistics views. The columns
remain of float8 type, so that sub-msec precision is available. (At some
point we will probably want to convert the core views to use float8 type
for the same reason, but this patch does not touch that issue.)
This is a release-note-requiring change in the meaning of the total_time
column. The I/O timing columns are new as of 9.2, so there is no
compatibility impact from redefining them.
Do some minor copy-editing in the documentation, too.
|
| |
|
|
|
|
|
|
|
| |
There's no need to sit there and increment the stats when we know all the
increments would be zero anyway. The actual additions might not be very
expensive, but skipping acquisition of the spinlock seems like a good
thing. Pushing the logic about initialization of the usage count down into
entry_alloc() allows us to do that while making the code actually simpler,
not more complex. Expansion on a suggestion by Peter Geoghegan.
|
| |
|
|
|
|
|
|
|
|
|
|
|
| |
This patch addresses a deficiency in the previous pg_stat_statements patch.
We want to give sticky entries an initial "usage" factor high enough that
they probably will stick around until their query is completed. However,
if the query never completes (eg it gets an error during execution), the
entry shouldn't persist indefinitely. Manage this by starting out with
a usage setting equal to the (approximate) median usage value within the
whole hashtable, but decaying the value much more aggressively than we
do for normal entries.
Peter Geoghegan
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
It's actually more useful for the module to ignore these. Ignoring
EXECUTE (and not incrementing the nesting level) allows the executor
hooks to charge the time to the underlying prepared query, which
shows up as a stats entry with the original PREPARE as query string
(possibly modified by suppression of constants, which might not be
terribly useful here but it's not worth avoiding). This is much more
useful than cluttering the stats table with a distinct entry for each
textually distinct EXECUTE.
Experimentation with this idea shows that it's also preferable to ignore
PREPARE. If we don't, we get two stats table entries, one with the query
string hash and one with the jumble-derived hash, but with the same visible
query string (modulo those constants). This is confusing and not very
helpful, since the first entry will only receive costs associated with
initial planning of the query, which is not something counted at all
normally by pg_stat_statements. (And if we do start tracking planning
costs, we'd want them blamed on the other hash table entry anyway.)
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
When tracking nested statements, contrib/pg_stat_statements formerly
double-counted the execution costs of utility statements that directly
contain an executable statement, such as EXPLAIN and DECLARE CURSOR.
This was not obvious since the ProcessUtility and Executor hooks
would each add their measured costs to the same stats table entry.
However, with the new implementation that hashes utility and plannable
statements differently, this showed up as seemingly-duplicate stats
entries. Fix that by disabling the Executor hooks when the query has a
queryId of zero, which was the case already for such statements but is now
more clearly specified in the code. (The zero queryId was causing problems
anyway because all such statements would add to a single bogus entry.)
The PREPARE/EXECUTE case still results in counting the same execution
in two different stats table entries, but it should be much less surprising
to users that there are two entries in such cases.
In passing, include a CommonTableExpr's ctename in the query hash.
I had left it out originally on the grounds that we wanted to omit all
inessential aliases, but since RTE_CTE RTEs are hashing their referenced
names, we'd better hash the CTE names too to make sure we don't hash
semantically different queries the same.
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
pg_stat_statements now hashes selected fields of the analyzed parse tree
to assign a "fingerprint" to each query, and groups all queries with the
same fingerprint into a single entry in the pg_stat_statements view.
In practice it is expected that queries with the same fingerprint will be
equivalent except for values of literal constants. To make the display
more useful, such constants are replaced by "?" in the displayed query
strings.
This mechanism currently supports only optimizable queries (SELECT,
INSERT, UPDATE, DELETE). Utility commands are still matched on the
basis of their literal query strings.
There remain some open questions about how to deal with utility statements
that contain optimizable queries (such as EXPLAIN and SELECT INTO) and how
to deal with expiring speculative hashtable entries that are made to save
the normalized form of a query string. However, fixing these issues should
require only localized changes, and since there are other open patches
involving contrib/pg_stat_statements, it seems best to go ahead and commit
what we've got.
Peter Geoghegan, reviewed by Daniel Farina
|
| |
|
|
| |
Ants Aasma, reviewed by Greg Smith, with very minor tweaks by me.
|
