Instead of passing "JsonbParseState **" to pushJsonbValue(),
pass a pointer to a JsonbInState, which will contain the
parseState stack pointer as well as other useful fields.
Also, instead of returning a JsonbValue pointer that is often
meaningless/ignored, return the top-level JsonbValue pointer
in the "result" field of the JsonbInState.
This involves a lot of (mostly mechanical) edits, but I think
the results are notationally cleaner and easier to understand.
Certainly the business with sometimes capturing the result of
pushJsonbValue() and sometimes not was bug-prone and incapable of
mechanical verification. In the new arrangement, JsonbInState.result
remains null until we've completed a valid sequence of pushes, so
that an incorrect sequence will result in a null-pointer dereference,
not mistaken use of a partial result.
However, this isn't simply an exercise in prettier notation.
The real reason for doing it is to provide a mechanism whereby
pushJsonbValue() can be told to construct the JsonbValue tree
in a context that is not CurrentMemoryContext. That happens
when a non-null "outcontext" is specified in the JsonbInState.
No callers exercise that option in this patch, but the next
patch in the series will make use of it.
I tried to improve the comments in this area too.
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: jian he <jian.universality@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/1060917.1753202222@sss.pgh.pa.us
pg_type.typlen says 12 for the size of timetz, but sizeof(TimeTzADT)
will be 16 on most platforms due to alignment padding. Using the
sizeof number is no problem for usages such as palloc'ing a result
datum, but in usages such as datumCopy we really ought to match
what pg_type says. Add a macro TIMETZ_TYPLEN so that we have a
symbolic way to write that rather than hard-coding "12".
I cannot find any place where we've needed this so far, but an
upcoming patch requires it.
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/2329959.1765047648@sss.pgh.pa.us
In an upcoming patch more wait events will be added to the wait event
class (for buffer locking), making the current name too
specific. Alternatively we could introduce a dedicated wait event class for
those, but it seems somewhat confusing to have a BUFFERPIN and a BUFFER wait
event class.
Reviewed-by: Melanie Plageman <melanieplageman@gmail.com>
Discussion: https://postgr.es/m/fvfmkr5kk4nyex56ejgxj3uzi63isfxovp2biecb4bspbjrze7@az2pljabhnff
Presently, this view reports NULL for the size of DSAs and dshash
tables because 1) the current backend might not be attached to them
and 2) the registry doesn't save the pointers to the dsa_area or
dshash_table in local memory. Also, the view doesn't show
partially-initialized entries to avoid ambiguity, since those
entries would report a NULL size as well.
This commit introduces a function that looks up the size of a DSA
given its handle (transiently attaching to the control segment if
needed) and teaches pg_dsm_registry_allocations to use it to show
the size of successfully-initialized DSA and dshash entries.
Furthermore, the view now reports partially-initialized entries
with a NULL size.
Reviewed-by: Rahila Syed <rahilasyed90@gmail.com>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/aSeEDeznAsHR1_YF%40nathan
This commit updates two functions that convert "timestamptz" to
"timestamp", and vice-versa, to use the soft error reporting rather than
a their own logic to do the same. These are now named as follows:
- timestamp2timestamptz_safe()
- timestamptz2timestamp_safe()
These functions were suffixed with "_opt_overflow", previously.
This shaves some code, as it is possible to detect how a timestamp[tz]
overflowed based on the returned value rather than a custom state. It
is optionally possible for the callers of these functions to rely on the
error generated internally by these functions, depending on the error
context.
Similar work has been done in d03668ea05 and 4246a977ba.
Reviewed-by: Amul Sul <sulamul@gmail.com>
Discussion: https://postgr.es/m/aS09YF2GmVXjAxbJ@paquier.xyz
The regex mechanism scans through the first "max_chr" character values
to cache character property ranges (isalpha, etc.). For single-byte
encodings, there's no sense in scanning beyond UCHAR_MAX; but for
UTF-8 it makes sense to cache higher code point values (though not all
of them; only up to MAX_SIMPLE_CHR).
Prior to 5a38104b36, the logic about how many character values to scan
was based on the pg_regex_strategy, which was dependent on the
provider. Commit 5a38104b36 preserved that logic exactly, allowing
different providers to define the "max_chr".
Now, change it to depend only on the encoding and whether
ctype_is_c. For this specific calculation, distinguishing between
providers creates more complexity than it's worth.
Discussion: https://postgr.es/m/450ceb6260cad30d7afdf155d991a9caafee7c0d.camel@j-davis.com
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
This commit changes some functions related to the data types date and
timestamp to use the soft error reporting rather than a custom boolean
flag called "overflow", used to let the callers of these functions know
if an overflow happens.
This results in the removal of some boilerplate code, as it is possible
to rely on an error context rather than a custom state, with the
possibility to use the error generated inside the functions updated
here, if necessary.
These functions were suffixed with "_opt_overflow". They are now
renamed to use "_safe" as suffix.
This work is similar to 4246a977ba.
Author: Amul Sul <sulamul@gmail.com>
Reviewed-by: Amit Langote <amitlangote09@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/CAAJ_b95HEmFyzHZfsdPquSHeswcopk8MCG1Q_vn4tVkZ+xxofw@mail.gmail.com
The code comment said, "It is expected that this routine will
eventually be replaced with the C99 hypot() function.", so let's do
that now.
This function is tested via the geometry regression test, so if it is
faulty on any platform, it will show up there.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/170308e6-a7a3-4484-87b2-f960bb564afa%40eisentraut.org
This commit renames write_chunk and read_chunk to respectively
pgstat_write_chunk() and pgstat_read_chunk(), along with the *_s
convenience macros.
These are made available for plug-ins, so as any code that decides to
write and/or read stats data can rely on a single code path for this
work.
Extracted from a larger patch by the same author.
Author: Sami Imseih <samimseih@gmail.com>
Discussion: https://postgr.es/m/CAA5RZ0s9SDOu+Z6veoJCHWk+kDeTktAtC-KY9fQ9Z6BJdDUirQ@mail.gmail.com
The existing range_minus function raises an exception when the range is
"split", because then the result can't be represented by a single range.
For example '[0,10)'::int4range - '[4,5)' would be '[0,4)' and '[5,10)'.
This commit adds new set-returning functions so that callers can get
results even in the case of splits. There is no risk of an exception for
multiranges, but a set-returning function lets us handle them the same
way we handle ranges.
Both functions return zero results if the subtraction would give an
empty range/multirange.
The main use-case for these functions is to implement UPDATE/DELETE FOR
PORTION OF, which must compute the application-time of "temporal
leftovers": the part of history in an updated/deleted row that was not
changed. To preserve the untouched history, we will implicitly insert
one record for each result returned by range/multirange_minus_multi.
Using a set-returning function will also let us support user-defined
types for application-time update/delete in the future.
Author: Paul A. Jungwirth <pj@illuminatedcomputing.com>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/ec498c3d-5f2b-48ec-b989-5561c8aa2024%40illuminatedcomputing.com
"long" is 32 bits on Windows 64-bit. Switch to a datatype that's 64-bit
on all platforms. While we're there, use an unsigned type as these
fields count things that have occurred, of which it's not possible to
have negative numbers of.
Author: David Rowley <dgrowleyml@gmail.com>
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://postgr.es/m/CAApHDvoGFjSA3aNyVQ3ivbyc4ST=CC5L-_VjEUQ92HbE2Cxovg@mail.gmail.com
guc_var_compare() is invoked from qsort() on an array of struct
config_generic, but the function accesses these directly as
strings (char *). This relies on the name being the first field, so
this works. But we can write this more clearly by using the struct
and then accessing the field through the struct. Before the
reorganization of the GUC structs (commit a13833c35f), the old code
was probably more convenient, but now we can write this more clearly
and correctly.
After this change, it is no longer required that the name is the first
field in struct config_generic, so remove that comment.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/2c961fa1-14f6-44a2-985c-e30b95654e8d%40eisentraut.org
Several functions in the codebase accept "Datum *" parameters but do
not modify the pointed-to data. These have been updated to take
"const Datum *" instead, improving type safety and making the
interfaces clearer about their intent. This change helps the compiler
catch accidental modifications and better documents immutability of
arguments.
Most of "Datum *" parameters have a pairing "bool *isnull" parameter,
they are constified as well.
No functional behavior is changed by this patch.
Author: Chao Li <lic@highgo.com>
Discussion: https://www.postgresql.org/message-id/flat/CAEoWx2msfT0knvzUa72ZBwu9LR_RLY4on85w2a9YpE-o2By5HQ@mail.gmail.com
Instead of having five separate GUC structs, one for each type, with
the generic part contained in each of them, flip it around and have
one common struct, with the type-specific part has a subfield.
The very original GUC design had type-specific structs and
type-specific lists, and the membership in one of the lists defined
the type. But now the structs themselves know the type (from the
.vartype field), and they are all loaded into a common hash table at
run time, and so this original separation no longer makes sense. It
creates a bunch of inconsistencies in the code about whether the
type-specific or the generic struct is the primary struct, and a lot
of casting in between, which makes certain assumptions about the
struct layouts.
After the change, all these casts are gone and all the data is
accessed via normal field references. Also, various code is
simplified because only one kind of struct needs to be processed.
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Discussion: https://www.postgresql.org/message-id/flat/8fdfb91e-60fb-44fa-8df6-f5dea47353c9@eisentraut.org
Per-character pg_locale_t APIs. Useful for tsearch parsing and
potentially other places.
Significant overlap with the regc_wc_isalpha() and related functions
in regc_pg_locale.c, but this change leaves those intact for
now.
Discussion: https://postgr.es/m/0151ad01239e2cc7b3139644358cf8f7b9622ff7.camel@j-davis.com
The log output functionality of log_autovacuum_min_duration applies to
both VACUUM and ANALYZE, so it is not possible to separate the VACUUM
and ANALYZE log output thresholds. Logs are likely to be output only for
VACUUM and not for ANALYZE.
Therefore, we decided to separate the threshold for log output of VACUUM
by autovacuum (log_autovacuum_min_duration) and the threshold for log
output of ANALYZE by autovacuum (log_autoanalyze_min_duration).
Author: Shinya Kato <shinya11.kato@gmail.com>
Reviewed-by: Kasahara Tatsuhito <kasaharatt@oss.nttdata.com>
Discussion: https://www.postgresql.org/message-id/flat/CAOzEurQtfV4MxJiWT-XDnimEeZAY+rgzVSLe8YsyEKhZcajzSA@mail.gmail.com
log_error() would probably fail completely if used, and would
certainly print garbage for anything that needed to be interpolated
into the message, because it was failing to use the correct printing
subroutine for a va_list argument.
This bug likely went undetected because the error cases this code
is used for are rarely exercised - they only occur when Windows
security API calls fail catastrophically (out of memory, security
subsystem corruption, etc).
The FRONTEND variant can be fixed just by calling vfprintf()
instead of fprintf(). However, there was no va_list variant
of write_stderr(), so create one by refactoring that function.
Following the usual naming convention for such things, call
it vwrite_stderr().
Author: Bryan Green <dbryan.green@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CAF+pBj8goe4fRmZ0V3Cs6eyWzYLvK+HvFLYEYWG=TzaM+tWPnw@mail.gmail.com
Backpatch-through: 13
In the same spirit as 3bf905692, assume that all compilers we still
support provide the NAN macro, and get rid of workarounds for that.
The C standard allows implementations to omit NAN if the underlying
float arithmetic lacks quiet (non-signaling) NaNs. However, we've
required that feature for years: the workarounds only supported
lack of the macro, not lack of the functionality. I put in a
compile-time #error if there's no macro, just for clarity.
Also fix up the copies of these functions in ecpglib, and leave
a breadcrumb for the next hacker who touches them.
History of the hacks being removed here can be found in commits
1bc2d544b, 4d17a2146, cec8394b5.
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/1952095.1759764279@sss.pgh.pa.us
It is possible to call pg_stat_reset_single_function_counters() for a
single function, but the reset time was missing the system view showing
its statistics. Like all the fields of pg_stat_user_functions, the GUC
track_functions needs to be enabled to show the statistics about
function executions.
Bump catalog version.
Bump PGSTAT_FILE_FORMAT_ID, as a result of the new field added to
PgStat_StatFuncEntry.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Discussion: https://postgr.es/m/aONjnsaJSx-nEdfU@paquier.xyz
The INFINITY macro is always defined per C99 standard, so this should
mean we can now get rid of the workaround code for when that macro isn't
defined.
Also, delete the (now unneeded) #pragma code which was disabling a
compiler warning in MSVC. There was a comment explaining why the #pragma
was placed outside the function body to work around a MSVC compiler bug,
but the link explaining that was dead, as reported by jian he.
Author: David Rowley <dgrowleyml@gmail.com>
Reported-by: jian he <jian.universality@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/CACJufxGARYETnNwtCK7QC0zE_7gq-tfN0mME=gT5rTNtC=VSHQ@mail.gmail.com
It is possible to call pg_stat_reset_single_table_counters() on a
relation (index or table) but the reset time was missing from the system
views showing their statistics.
This commit adds the reset time as an attribute of pg_stat_all_tables,
pg_stat_all_indexes, and other relations related to them.
Bump catalog version.
Bump PGSTAT_FILE_FORMAT_ID, as a result of the new field added to
PgStat_StatTabEntry.
Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Sami Imseih <samimseih@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/aN8l182jKxEq1h9f@paquier.xyz
Stats kinds can set a new option called "track_entry_count" (disabled by
default, available for variable-numbered stats) that will make pgstats
track the number of entries that exist in its shared hashtable.
As there is only one code path where a new entry is added, and one code
path where entries are freed, the count tracking is straight-forward in
its implementation. Reads of these counters are optimistic, and may
change across two calls. The counter is incremented when an entry is
created (not when reused), and is decremented when an entry is freed
from the hashtable (marked for drop with its refcount reaching 0), which
is something that pgstats decides internally.
A first use case of this facility would be pg_stat_statements, where we
need to be able to cap the number of entries that would be stored in the
shared hashtable, based on its "max" GUC. The module currently relies
on hash_get_num_entries(), which offers a cheap way to count how many
entries are in its hash table, but we cannot do that in pgstats for
variable-sized stats kinds as a single hashtable is used for all the
stats kinds. Independently of PGSS, this is useful for other custom
stats kinds that want to cap, control, or track the number of entries
they have, without depending on a potentially expensive sequential scan
to know the number of entries while holding an extra exclusive lock.
Author: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Sami Imseih <samimseih@gmail.com>
Reviewed-by: Keisuke Kuroda <keisuke.kuroda.3862@gmail.com>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/aMPKWR81KT5UXvEr@paquier.xyz
It had always been intended that this already works correctly as
pg_unreachable() uses __assume(0) on MSVC, and that directs the compiler
in a way so it knows that a given function won't return. However, with
ereport_domain(), it didn't work...
It's now understood that the failure to determine that elog(ERROR) does not
return comes from the inability of the MSVC compiler to detect the "const
int elevel_" is the same as the "elevel" macro parameter. MSVC seems to be
unable to make the "if (elevel_ >= ERROR) branch constantly-true when the
macro is used with any elevel >= ERROR, therefore the pg_unreachable() is
seen to only be present in a *conditional* branch rather than present
*unconditionally*.
While there seems to be no way to force the compiler into knowing that
elevel_ is equal to elevel within the ereport_domain() macro, there is a
way in C11 to determine if the elevel parameter is a compile-time
constant or not. This is done via some hackery using the _Generic()
intrinsic function, which gives us functionality similar to GCC's
__builtin_constant_p(), albeit only for integers.
Here we define pg_builtin_integer_constant_p() for this purpose.
Callers can check for availability via HAVE_PG_BUILTIN_INTEGER_CONSTANT_P.
ereport_domain() has been adjusted to use
pg_builtin_integer_constant_p() instead of __builtin_constant_p().
It's not quite clear at this stage if this now allows us to forego doing
the likes of "return NULL; /* keep compiler quiet */" as there may be other
compilers in use that have similar struggles. It's just a matter of time
before someone commits a function that does not "return" a value after
an elog(ERROR). Let's make time and lack of complaints about said commit
be the judge of if we need to continue the "/* keep compiler quiet */"
palaver.
Author: David Rowley <drowleyml@gmail.com>
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://postgr.es/m/CAApHDvom02B_XNVSkvxznVUyZbjGAR+5myA89ZcbEd3=PA9UcA@mail.gmail.com
This change is a tighter rework of 7d85d87f4d, which tried to improve
the code so as it would work should PgStat_HashKey gain new fields that
create padding bytes. However, the previous change is proving to not be
enough as some code paths of pgstats do not pass PgStat_HashKey by
reference (valgrind would warn when padding is added to the structure,
through a new field).
Per discussion, let's document and check that PgStat_HashKey has no
padding rather than try to complicate the code of pgstats so as it is
able to work around that.
This removes a couple of memset(0) calls that should not be required.
While on it, this commit adds a static assertion checking that no
padding is introduced in the structure, by checking that the size of
PgStat_HashKey matches with the sum of the size of all its fields.
The object ID part of the hash key is already 8 bytes, which should be
plenty enough already. A comment is added to discourage the addition of
new fields.
Author: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Sami Imseih <samimseih@gmail.com>
Discussion: https://postgr.es/m/CAA5RZ0t9omat+HVSakJXwTMWvhpYFcAZb41RPWKwrKFUgmAFBQ@mail.gmail.com
fmgr.h defined some types such as fmNodePtr which is just Node *, but
it made its own types to avoid having to include various header files.
With C11, we can now instead typedef the original names without fear
of conflicts.
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/10d32190-f31b-40a5-b177-11db55597355@eisentraut.org
There are a number of forward declarations that use struct but not the
customary typedef, because that could have led to repeat typedefs,
which was not allowed. This is now allowed in C11, so we can update
these to provide the typedefs as well, so that the later uses of the
types look more consistent.
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/10d32190-f31b-40a5-b177-11db55597355@eisentraut.org
GucSource_Names was documented as being in guc.c, but since 0a20ff54f5
it is located in guc_tables.c. The reference to the location of
GucSource_Names is important, as GucSource needs to be kept in sync with
GucSource_Names.
Author: David G. Johnston <david.g.johnston@gmail.com>
Discussion: https://postgr.es/m/CAKFQuwYPgAHWPYjPzK7iXzhSZ6MKR8w20_Nz7ZXpOvx=kZbs7A@mail.gmail.com
Backpatch-through: 16
This commit allows to log the raw parse tree in the same way we
currently log the parse tree, rewritten tree, and plan tree.
To avoid unnecessary log noise for users not interested in this
detail, a new GUC option, "debug_print_raw_parse", has been added.
When starting the PostgreSQL process with "-d N", and N is 3 or higher,
debug_print_raw_parse is enabled automatically, alongside
debug_print_parse.
Author: Chao Li <lic@highgo.com>
Reviewed-by: Tender Wang <tndrwang@gmail.com>
Reviewed-by: Tatsuo Ishii <ishii@postgresql.org>
Reviewed-by: John Naylor <johncnaylorls@gmail.com>
Discussion: https://postgr.es/m/CAEoWx2mcO0Gpo4vd8kPMAFWeJLSp0MeUUnaLdE1x0tSVd-VzUw%40mail.gmail.com
This commit changes some functions related to the data type numeric to
use the soft error reporting rather than a custom boolean flag (called
"have_error") that callers of these functions could rely on to bypass
the generation of ERROR reports, letting the callers do their own error
handling (timestamp, jsonpath and numeric_to_char() require them).
This results in the removal of some boilerplate code that was required
to handle both the ereport() and the "have_error" code paths bypassing
ereport(), unifying everything under the soft error reporting facility.
While on it, some duplicated error messages are removed. The function
upgraded in this commit were suffixed with "_opt_error" in their names.
They are renamed to "_safe" instead.
This change relies on d9f7f5d32f, that has introduced the soft error
reporting infrastructure.
Author: Amul Sul <sulamul@gmail.com>
Reviewed-by: Dean Rasheed <dean.a.rasheed@gmail.com>
Discussion: https://postgr.es/m/CAAJ_b96No5h5tRuR+KhcC44YcYUCw8WAHuLoqqyyop8_k3+JDQ@mail.gmail.com
pg_lsn includes pg_lsn_in_internal() for the purpose of parsing a LSN
position for the GUC recovery_target_lsn (21f428ebde). It relies on a
boolean called "have_error" that would be set when the LSN parsing
fails, then let its callers handle any errors.
d9f7f5d32f has added support for soft error reporting. This commit
removes some boilerplate code and switches the routine to use soft error
reporting directly, giving to the callers of pg_lsn_in_internal()
the possibility to be fed the error message generated on failure.
pg_lsn_in_internal() routine is renamed to pg_lsn_in_safe(), for
consistency with other similar routines that are given an escontext.
Author: Amul Sul <sulamul@gmail.com>
Reviewed-by: Dean Rasheed <dean.a.rasheed@gmail.com>
Discussion: https://postgr.es/m/CAAJ_b96No5h5tRuR+KhcC44YcYUCw8WAHuLoqqyyop8_k3+JDQ@mail.gmail.com
Store the information in guc_tables.c in a .dat file similar to the
catalog data in src/include/catalog/, and generate a part of
guc_tables.c from that. The goal is to make it easier to edit that
information, and to be able to make changes to the downstream data
structures more easily. (Essentially, those are the same reasons as
for the original adoption of the .dat format.)
Reviewed-by: John Naylor <johncnaylorls@gmail.com>
Reviewed-by: Daniel Gustafsson <daniel@yesql.se>
Reviewed-by: David E. Wheeler <david@justatheory.com>
Discussion: https://www.postgresql.org/message-id/flat/dae6fe89-1e0c-4c3f-8d92-19d23374fb10%40eisentraut.org
This has been done historically because of get_database_name (which
since commit cb98e6fb8f belongs in lsyscache.c/h, so let's move it
there) and get_database_oid (which is in the right place, but whose
declaration should appear in pg_database.h rather than dbcommands.h).
Clean this up.
Also, xlogreader.h and stringinfo.h are no longer needed by dbcommands.h
since commit f1fd515b39, so remove them.
Author: Álvaro Herrera <alvherre@kurilemu.de>
Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/202508191031.5ipojyuaswzt@alvherre.pgsql
Commit 1585ff7387 changed GetTransactionSnapshot() to throw an error
if it's called during logical decoding, instead of returning the
historic snapshot. I made that change for extra protection, because a
historic snapshot can only be used to access catalog tables while
GetTransactionSnapshot() is usually called when you're executing
arbitrary queries. You might get very subtle visibility problems if
you tried to use the historic snapshot for arbitrary queries.
There's no built-in code in PostgreSQL that calls
GetTransactionSnapshot() during logical decoding, but it turns out
that the pglogical extension does just that, to evaluate row filter
expressions. You would get weird results if the row filter runs
arbitrary queries, but it is sane as long as you don't access any
non-catalog tables. Even though there are no checks to enforce that in
pglogical, a typical row filter expression does not access any tables
and works fine. Accessing tables marked with the user_catalog_table =
true option is also OK.
To fix pglogical with row filters, and any other extensions that might
do similar things, revert GetTransactionSnapshot() to return a
historic snapshot during logical decoding.
To try to still catch the unsafe usage of historic snapshots, add
checks in heap_beginscan() and index_beginscan() to complain if you
try to use a historic snapshot to scan a non-catalog table. We're very
close to the version 18 release however, so add those new checks only
in master.
Backpatch-through: 18
Reported-by: Noah Misch <noah@leadboat.com>
Reviewed-by: Noah Misch <noah@leadboat.com>
Discussion: https://www.postgresql.org/message-id/20250809222338.cc.nmisch@google.com
This code was relying on "long", which is signed 8 bytes everywhere
except on Windows where it is 4 bytes, that could potentially expose it
to overflows, even if the current uses in the code are fine as far as I
know. This code is now able to rely on the same sizeof() variable
everywhere, with int64. long was used for sizes, partition counts and
entry counts.
Some callers of the dynahash.c routines used long declarations, that can
be cleaned up to use int64 instead. There was one shortcut based on
SIZEOF_LONG, that can be removed. long is entirely removed from
dynahash.c and hsearch.h.
Similar work was done in b1e5c9fa9a.
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Discussion: https://postgr.es/m/aKQYp-bKTRtRauZ6@paquier.xyz
