Commit Graph

1714 Commits

Author SHA1 Message Date
Heikki Linnakangas c619c2351f Move pg_crc.c to src/common, and remove pg_crc_tables.h
To get CRC functionality in a client program, you now need to link with
libpgcommon instead of libpgport. The CRC code has nothing to do with
portability, so libpgcommon is a better home. (libpgcommon didn't exist
when pg_crc.c was originally moved to src/port.)

Remove the possibility to get CRC functionality by just #including
pg_crc_tables.h. I'm not aware of any extensions that actually did that and
couldn't simply link with libpgcommon.

This also moves the pg_crc.h header file from src/include/utils to
src/include/common, which will require changes to any external programs
that currently does #include "utils/pg_crc.h". That seems acceptable, as
include/common is clearly the right home for it now, and the change needed
to any such programs is trivial.
2015-02-09 11:17:56 +02:00
Fujii Masao 40bede5477 Move pg_lzcompress.c to src/common.
The meta data of PGLZ symbolized by PGLZ_Header is removed, to make
the compression and decompression code independent on the backend-only
varlena facility. PGLZ_Header is being used to store some meta data
related to the data being compressed like the raw length of the uncompressed
record or some varlena-related data, making it unpluggable once PGLZ is
stored in src/common as it contains some backend-only code paths with
the management of varlena structures. The APIs of PGLZ are reworked
at the same time to do only compression and decompression of buffers
without the meta-data layer, simplifying its use for a more general usage.

On-disk format is preserved as well, so there is no incompatibility with
previous major versions of PostgreSQL for TOAST entries.

Exposing compression and decompression APIs of pglz makes possible its
use by extensions and contrib modules. Especially this commit is required
for upcoming WAL compression feature so that the WAL reader facility can
decompress the WAL data by using pglz_decompress.

Michael Paquier, reviewed by me.
2015-02-09 15:15:24 +09:00
Tom Lane cec916f35b Remove unused "m" field in LSEG.
This field has been unreferenced since 1998, and does not appear in lseg
values stored on disk (since sizeof(lseg) is only 32 bytes according to
pg_type).  There was apparently some idea of maintaining it just in values
appearing in memory, but the bookkeeping required to make that work would
surely far outweigh the cost of recalculating the line's slope when needed.
Remove it to (a) simplify matters and (b) suppress some uninitialized-field
whining from Coverity.
2015-02-03 16:53:32 -05:00
Robert Haas bd4e2fd97d Provide a way to supress the "out of memory" error when allocating.
Using the new interface MemoryContextAllocExtended, callers can
specify MCXT_ALLOC_NO_OOM if they are prepared to handle a NULL
return value.

Michael Paquier, reviewed and somewhat revised by me.
2015-01-30 12:56:48 -05:00
Stephen Frost 804b6b6db4 Fix column-privilege leak in error-message paths
While building error messages to return to the user,
BuildIndexValueDescription, ExecBuildSlotValueDescription and
ri_ReportViolation would happily include the entire key or entire row in
the result returned to the user, even if the user didn't have access to
view all of the columns being included.

Instead, include only those columns which the user is providing or which
the user has select rights on.  If the user does not have any rights
to view the table or any of the columns involved then no detail is
provided and a NULL value is returned from BuildIndexValueDescription
and ExecBuildSlotValueDescription.  Note that, for key cases, the user
must have access to all of the columns for the key to be shown; a
partial key will not be returned.

Further, in master only, do not return any data for cases where row
security is enabled on the relation and row security should be applied
for the user.  This required a bit of refactoring and moving of things
around related to RLS- note the addition of utils/misc/rls.c.

Back-patch all the way, as column-level privileges are now in all
supported versions.

This has been assigned CVE-2014-8161, but since the issue and the patch
have already been publicized on pgsql-hackers, there's no point in trying
to hide this commit.
2015-01-28 12:31:30 -05:00
Tom Lane 4b2a254793 Add a note to PG_TRY's documentation about volatile safety.
We had better memorialize what the actual requirements are for this.
2015-01-26 15:53:37 -05:00
Robert Haas d1747571b6 Fix typos, update README.
Peter Geoghegan
2015-01-23 15:06:53 -05:00
Robert Haas 4ea51cdfe8 Use abbreviated keys for faster sorting of text datums.
This commit extends the SortSupport infrastructure to allow operator
classes the option to provide abbreviated representations of Datums;
in the case of text, we abbreviate by taking the first few characters
of the strxfrm() blob.  If the abbreviated comparison is insufficent
to resolve the comparison, we fall back on the normal comparator.
This can be much faster than the old way of doing sorting if the
first few bytes of the string are usually sufficient to resolve the
comparison.

There is the potential for a performance regression if all of the
strings to be sorted are identical for the first 8+ characters and
differ only in later positions; therefore, the SortSupport machinery
now provides an infrastructure to abort the use of abbreviation if
it appears that abbreviation is producing comparatively few distinct
keys.  HyperLogLog, a streaming cardinality estimator, is included in
this commit and used to make that determination for text.

Peter Geoghegan, reviewed by me.
2015-01-19 15:28:27 -05:00
Heikki Linnakangas 9402869160 Advance backend's advertised xmin more aggressively.
Currently, a backend will reset it's PGXACT->xmin value when it doesn't
have any registered snapshots left. That covered the common case that a
transaction in read committed mode runs several queries, one after each
other, as there would be no snapshots active between those queries.
However, if you hold cursors across each of the query, we didn't get a
chance to reset xmin.

To make that better, keep all the registered snapshots in a pairing heap,
ordered by xmin so that it's always quick to find the snapshot with the
smallest xmin. That allows us to advance PGXACT->xmin whenever the oldest
snapshot is deregistered, even if there are others still active.

Per discussion originally started by Jeff Davis back in 2009 and more
recently by Robert Haas.
2015-01-17 01:15:23 +02:00
Tom Lane a5cd70dcbc Improve performance of EXPLAIN with large range tables.
As of 9.3, ruleutils.c goes to some lengths to ensure that table and column
aliases used in its output are unique.  Of course this takes more time than
was required before, which in itself isn't fatal.  However, EXPLAIN was set
up so that recalculation of the unique aliases was repeated for each
subexpression printed in a plan.  That results in O(N^2) time and memory
consumption for large plan trees, which did not happen in older branches.

Fortunately, the expensive work is the same across a whole plan tree,
so there is no need to repeat it; we can do most of the initialization
just once per query and re-use it for each subexpression.  This buys
back most (not all) of the performance loss since 9.2.

We need an extra ExplainState field to hold the precalculated deparse
context.  That's no problem in HEAD, but in the back branches, expanding
sizeof(ExplainState) seems risky because third-party extensions might
have local variables of that struct type.  So, in 9.4 and 9.3, introduce
an auxiliary struct to keep sizeof(ExplainState) the same.  We should
refactor the APIs to avoid such local variables in future, but that's
material for a separate HEAD-only commit.

Per gripe from Alexey Bashtanov.  Back-patch to 9.3 where the issue
was introduced.
2015-01-15 13:18:12 -05:00
Bruce Momjian 4baaf863ec Update copyright for 2015
Backpatch certain files through 9.0
2015-01-06 11:43:47 -05:00
Alvaro Herrera a676201490 Add pg_identify_object_as_address
This function returns object type and objname/objargs arrays, which can
be passed to pg_get_object_address.  This is especially useful because
the textual representation can be copied to a remote server in order to
obtain the corresponding OID-based address.  In essence, this function
is the inverse of recently added pg_get_object_address().

Catalog version bumped due to the addition of the new function.

Also add docs to pg_get_object_address.
2014-12-30 15:41:50 -03:00
Tom Lane 966115c305 Temporarily revert "Move pg_lzcompress.c to src/common."
This reverts commit 60838df922.
That change needs a bit more thought to be workable.  In view of
the potentially machine-dependent stuff that went in today,
we need all of the buildfarm to be testing those other changes.
2014-12-25 13:22:55 -05:00
Andres Freund 570bd2b3fd Add capability to suppress CONTEXT: messages to elog machinery.
Hiding context messages usually is not a good idea - except for rather
verbose debugging/development utensils like LOG_DEBUG. There the
amount of repeated context messages just bloat the log without adding
information.
2014-12-25 17:24:30 +01:00
Fujii Masao 60838df922 Move pg_lzcompress.c to src/common.
Exposing compression and decompression APIs of pglz makes possible its
use by extensions and contrib modules. pglz_decompress contained a call
to elog to emit an error message in case of corrupted data. This function
is changed to return a status code to let its callers return an error instead.

This commit is required for upcoming WAL compression feature so that
the WAL reader facility can decompress the WAL data by using pglz_decompress.

Michael Paquier
2014-12-25 20:46:14 +09:00
Alvaro Herrera a609d96778 Revert "Use a bitmask to represent role attributes"
This reverts commit 1826987a46.

The overall design was deemed unacceptable, in discussion following the
previous commit message; we might find some parts of it still
salvageable, but I don't want to be on the hook for fixing it, so let's
wait until we have a new patch.
2014-12-23 15:35:49 -03:00
Alvaro Herrera d7ee82e50f Add SQL-callable pg_get_object_address
This allows access to get_object_address from SQL, which is useful to
obtain OID addressing information from data equivalent to that emitted
by the parser.  This is necessary infrastructure of a project to let
replication systems propagate object dropping events to remote servers,
where the schema might be different than the server originating the
DROP.

This patch also adds support for OBJECT_DEFAULT to get_object_address;
that is, it is now possible to refer to a column's default value.

Catalog version bumped due to the new function.

Reviewed by Stephen Frost, Heikki Linnakangas, Robert Haas, Andres
Freund, Abhijit Menon-Sen, Adam Brightwell.
2014-12-23 15:31:29 -03:00
Alvaro Herrera 1826987a46 Use a bitmask to represent role attributes
The previous representation using a boolean column for each attribute
would not scale as well as we want to add further attributes.

Extra auxilliary functions are added to go along with this change, to
make up for the lost convenience of access of the old representation.

Catalog version bumped due to change in catalogs and the new functions.

Author: Adam Brightwell, minor tweaks by Álvaro
Reviewed by: Stephen Frost, Andres Freund, Álvaro Herrera
2014-12-23 10:22:09 -03:00
Heikki Linnakangas 955557ddcc Move rbtree.c from src/backend/utils/misc to src/backend/lib.
We have other general-purpose data structures in src/backend/lib, so it
seems like a better home for the red-black tree as well.
2014-12-22 17:52:08 +02:00
Tom Lane 4a14f13a0a Improve hash_create's API for selecting simple-binary-key hash functions.
Previously, if you wanted anything besides C-string hash keys, you had to
specify a custom hashing function to hash_create().  Nearly all such
callers were specifying tag_hash or oid_hash; which is tedious, and rather
error-prone, since a caller could easily miss the opportunity to optimize
by using hash_uint32 when appropriate.  Replace this with a design whereby
callers using simple binary-data keys just specify HASH_BLOBS and don't
need to mess with specific support functions.  hash_create() itself will
take care of optimizing when the key size is four bytes.

This nets out saving a few hundred bytes of code space, and offers
a measurable performance improvement in tidbitmap.c (which was not
exploiting the opportunity to use hash_uint32 for its 4-byte keys).
There might be some wins elsewhere too, I didn't analyze closely.

In future we could look into offering a similar optimized hashing function
for 8-byte keys.  Under this design that could be done in a centralized
and machine-independent fashion, whereas getting it right for keys of
platform-dependent sizes would've been notationally painful before.

For the moment, the old way still works fine, so as not to break source
code compatibility for loadable modules.  Eventually we might want to
remove tag_hash and friends from the exported API altogether, since there's
no real need for them to be explicitly referenced from outside dynahash.c.

Teodor Sigaev and Tom Lane
2014-12-18 13:36:36 -05:00
Heikki Linnakangas 4520ba6769 Add point <-> polygon distance operator.
Alexander Korotkov, reviewed by Emre Hasegeli.
2014-12-15 17:06:21 +02:00
Andrew Dunstan 7e354ab9fe Add several generator functions for jsonb that exist for json.
The functions are:
    to_jsonb()
    jsonb_object()
    jsonb_build_object()
    jsonb_build_array()
    jsonb_agg()
    jsonb_object_agg()

Also along the way some better logic is implemented in
json_categorize_type() to match that in the newly implemented
jsonb_categorize_type().

Andrew Dunstan, reviewed by Pavel Stehule and Alvaro Herrera.
2014-12-12 15:31:14 -05:00
Andrew Dunstan 237a882443 Add json_strip_nulls and jsonb_strip_nulls functions.
The functions remove object fields, including in nested objects, that
have null as a value. In certain cases this can lead to considerably
smaller datums, with no loss of semantic information.

Andrew Dunstan, reviewed by Pavel Stehule.
2014-12-12 09:00:43 -05:00
Simon Riggs 618c9430a8 Event Trigger for table_rewrite
Generate a table_rewrite event when ALTER TABLE
attempts to rewrite a table. Provide helper
functions to identify table and reason.

Intended use case is to help assess or to react
to schema changes that might hold exclusive locks
for long periods.

Dimitri Fontaine, triggering an edit by Simon Riggs

Reviewed in detail by Michael Paquier
2014-12-08 00:55:28 +09:00
Peter Eisentraut e86507d770 Move PG_AUTOCONF_FILENAME definition
Since this is not something that a user should change,
pg_config_manual.h was an inappropriate place for it.

In initdb.c, remove the use of the macro, because utils/guc.h can't be
included by non-backend code.  But we hardcode all the other
configuration file names there, so this isn't a disaster.
2014-12-03 19:54:01 -05:00
Alvaro Herrera 73c986adde Keep track of transaction commit timestamps
Transactions can now set their commit timestamp directly as they commit,
or an external transaction commit timestamp can be fed from an outside
system using the new function TransactionTreeSetCommitTsData().  This
data is crash-safe, and truncated at Xid freeze point, same as pg_clog.

This module is disabled by default because it causes a performance hit,
but can be enabled in postgresql.conf requiring only a server restart.

A new test in src/test/modules is included.

Catalog version bumped due to the new subdirectory within PGDATA and a
couple of new SQL functions.

Authors: Álvaro Herrera and Petr Jelínek

Reviewed to varying degrees by Michael Paquier, Andres Freund, Robert
Haas, Amit Kapila, Fujii Masao, Jaime Casanova, Simon Riggs, Steven
Singer, Peter Eisentraut
2014-12-03 11:53:02 -03:00
Andrew Dunstan e09996ff8d Fix hstore_to_json_loose's detection of valid JSON number values.
We expose a function IsValidJsonNumber that internally calls the lexer
for json numbers. That allows us to use the same test everywhere,
instead of inventing a broken test for hstore conversions. The new
function is also used in datum_to_json, replacing the code that is now
moved to the new function.

Backpatch to 9.3 where hstore_to_json_loose was introduced.
2014-12-01 11:28:45 -05:00
Stephen Frost 143b39c185 Rename pg_rowsecurity -> pg_policy and other fixes
As pointed out by Robert, we should really have named pg_rowsecurity
pg_policy, as the objects stored in that catalog are policies.  This
patch fixes that and updates the column names to start with 'pol' to
match the new catalog name.

The security consideration for COPY with row level security, also
pointed out by Robert, has also been addressed by remembering and
re-checking the OID of the relation initially referenced during COPY
processing, to make sure it hasn't changed under us by the time we
finish planning out the query which has been built.

Robert and Alvaro also commented on missing OCLASS and OBJECT entries
for POLICY (formerly ROWSECURITY or POLICY, depending) in various
places.  This patch fixes that too, which also happens to add the
ability to COMMENT on policies.

In passing, attempt to improve the consistency of messages, comments,
and documentation as well.  This removes various incarnations of
'row-security', 'row-level security', 'Row-security', etc, in favor
of 'policy', 'row level security' or 'row_security' as appropriate.

Happy Thanksgiving!
2014-11-27 01:15:57 -05:00
Tom Lane bac27394a1 Support arrays as input to array_agg() and ARRAY(SELECT ...).
These cases formerly failed with errors about "could not find array type
for data type".  Now they yield arrays of the same element type and one
higher dimension.

The implementation involves creating functions with API similar to the
existing accumArrayResult() family.  I (tgl) also extended the base family
by adding an initArrayResult() function, which allows callers to avoid
special-casing the zero-inputs case if they just want an empty array as
result.  (Not all do, so the previous calling convention remains valid.)
This allowed simplifying some existing code in xml.c and plperl.c.

Ali Akbar, reviewed by Pavel Stehule, significantly modified by me
2014-11-25 12:21:28 -05:00
Robert Haas f5d9698a84 Add infrastructure to save and restore GUC values.
This is further infrastructure for parallelism.

Amit Khandekar, Noah Misch, Robert Haas
2014-11-24 16:37:56 -05:00
Heikki Linnakangas 2c03216d83 Revamp the WAL record format.
Each WAL record now carries information about the modified relation and
block(s) in a standardized format. That makes it easier to write tools that
need that information, like pg_rewind, prefetching the blocks to speed up
recovery, etc.

There's a whole new API for building WAL records, replacing the XLogRecData
chains used previously. The new API consists of XLogRegister* functions,
which are called for each buffer and chunk of data that is added to the
record. The new API also gives more control over when a full-page image is
written, by passing flags to the XLogRegisterBuffer function.

This also simplifies the XLogReadBufferForRedo() calls. The function can dig
the relation and block number from the WAL record, so they no longer need to
be passed as arguments.

For the convenience of redo routines, XLogReader now disects each WAL record
after reading it, copying the main data part and the per-block data into
MAXALIGNed buffers. The data chunks are not aligned within the WAL record,
but the redo routines can assume that the pointers returned by XLogRecGet*
functions are. Redo routines are now passed the XLogReaderState, which
contains the record in the already-disected format, instead of the plain
XLogRecord.

The new record format also makes the fixed size XLogRecord header smaller,
by removing the xl_len field. The length of the "main data" portion is now
stored at the end of the WAL record, and there's a separate header after
XLogRecord for it. The alignment padding at the end of XLogRecord is also
removed. This compansates for the fact that the new format would otherwise
be more bulky than the old format.

Reviewed by Andres Freund, Amit Kapila, Michael Paquier, Alvaro Herrera,
Fujii Masao.
2014-11-20 18:46:41 +02:00
Alvaro Herrera 0f9692b40d Fix relpersistence setting in reindex_index
Buildfarm members with CLOBBER_CACHE_ALWAYS advised us that commit
85b506bbfc was mistaken in setting the relpersistence value of the
index directly in the relcache entry, within reindex_index.  The reason
for the failure is that an invalidation message that comes after mucking
with the relcache entry directly, but before writing it to the catalogs,
would cause the entry to become rebuilt in place from catalogs with the
old contents, losing the update.

Fix by passing the correct persistence value to
RelationSetNewRelfilenode instead; this routine also writes the updated
tuple to pg_class, avoiding the problem.  Suggested by Tom Lane.
2014-11-17 11:23:35 -03:00
Stephen Frost 80eacaa3cd Clean up includes from RLS patch
The initial patch for RLS mistakenly included headers associated with
the executor and planner bits in rewrite/rowsecurity.h.  Per policy and
general good sense, executor headers should not be included in planner
headers or vice versa.

The include of execnodes.h was a mistaken holdover from previous
versions, while the include of relation.h was used for Relation's
definition, which should have been coming from utils/relcache.h.  This
patch cleans these issues up, adds comments to the RowSecurityPolicy
struct and the RowSecurityConfigType enum, and changes Relation->rsdesc
to Relation->rd_rsdesc to follow Relation field naming convention.

Additionally, utils/rel.h was including rewrite/rowsecurity.h, which
wasn't a great idea since that was pulling in things not really needed
in utils/rel.h (which gets included in quite a few places).  Instead,
use 'struct RowSecurityDesc' for the rd_rsdesc field and add comments
explaining why.

Lastly, add an include into access/nbtree/nbtsort.c for
utils/sortsupport.h, which was evidently missed due to the above mess.

Pointed out by Tom in 16970.1415838651@sss.pgh.pa.us; note that the
concerns regarding a similar situation in the custom-path commit still
need to be addressed.
2014-11-14 17:05:17 -05:00
Robert Haas c0828b78e9 Move the guts of our Levenshtein implementation into core.
The hope is that we can use this to produce better diagnostics in
some cases.

Peter Geoghegan, reviewed by Michael Paquier, with some further
changes by me.
2014-11-13 12:33:26 -05:00
Tom Lane 677708032c Explicitly support the case that a plancache's raw_parse_tree is NULL.
This only happens if a client issues a Parse message with an empty query
string, which is a bit odd; but since it is explicitly called out as legal
by our FE/BE protocol spec, we'd probably better continue to allow it.

Fix by adding tests everywhere that the raw_parse_tree field is passed to
functions that don't or shouldn't accept NULL.  Also make it clear in the
relevant comments that NULL is an expected case.

This reverts commits a73c9dbab0 and
2e9650cbcf, which fixed specific crash
symptoms by hacking things at what now seems to be the wrong end, ie the
callee functions.  Making the callees allow NULL is superficially more
robust, but it's not always true that there is a defensible thing for the
callee to do in such cases.  The caller has more context and is better
able to decide what the empty-query case ought to do.

Per followup discussion of bug #11335.  Back-patch to 9.2.  The code
before that is sufficiently different that it would require development
of a separate patch, which doesn't seem worthwhile for what is believed
to be an essentially cosmetic change.
2014-11-12 15:59:01 -05:00
Fujii Masao 1871c89202 Add generate_series(numeric, numeric).
Платон Малюгин
Reviewed by Michael Paquier, Ali Akbar and Marti Raudsepp
2014-11-11 21:44:46 +09:00
Fujii Masao a1b395b6a2 Add GUC and storage parameter to set the maximum size of GIN pending list.
Previously the maximum size of GIN pending list was controlled only by
work_mem. But the reasonable value of work_mem and the reasonable size
of the list are basically not the same, so it was not appropriate to
control both of them by only one GUC, i.e., work_mem. This commit
separates new GUC, pending_list_cleanup_size, from work_mem to allow
users to control only the size of the list.

Also this commit adds pending_list_cleanup_size as new storage parameter
to allow users to specify the size of the list per index. This is useful,
for example, when users want to increase the size of the list only for
the GIN index which can be updated heavily, and decrease it otherwise.

Reviewed by Etsuro Fujita.
2014-11-11 21:08:21 +09:00
Bruce Momjian 67067f9ae3 C comment: mention 1500-02-29 as an invalid date
It is invalid because the Gregorian calendar is used for all years.
2014-11-09 20:50:15 -05:00
Robert Haas 5ea86e6e65 Use the sortsupport infrastructure in more cases.
This removes some fmgr overhead from cases such as btree index builds.

Peter Geoghegan, reviewed by Andreas Karlsson and me.
2014-11-07 15:50:55 -05:00
Alvaro Herrera 7516f52594 BRIN: Block Range Indexes
BRIN is a new index access method intended to accelerate scans of very
large tables, without the maintenance overhead of btrees or other
traditional indexes.  They work by maintaining "summary" data about
block ranges.  Bitmap index scans work by reading each summary tuple and
comparing them with the query quals; all pages in the range are returned
in a lossy TID bitmap if the quals are consistent with the values in the
summary tuple, otherwise not.  Normal index scans are not supported
because these indexes do not store TIDs.

As new tuples are added into the index, the summary information is
updated (if the block range in which the tuple is added is already
summarized) or not; in the latter case, a subsequent pass of VACUUM or
the brin_summarize_new_values() function will create the summary
information.

For data types with natural 1-D sort orders, the summary info consists
of the maximum and the minimum values of each indexed column within each
page range.  This type of operator class we call "Minmax", and we
supply a bunch of them for most data types with B-tree opclasses.
Since the BRIN code is generalized, other approaches are possible for
things such as arrays, geometric types, ranges, etc; even for things
such as enum types we could do something different than minmax with
better results.  In this commit I only include minmax.

Catalog version bumped due to new builtin catalog entries.

There's more that could be done here, but this is a good step forwards.

Loosely based on ideas from Simon Riggs; code mostly by Álvaro Herrera,
with contribution by Heikki Linnakangas.

Patch reviewed by: Amit Kapila, Heikki Linnakangas, Robert Haas.
Testing help from Jeff Janes, Erik Rijkers, Emanuel Calvo.

PS:
  The research leading to these results has received funding from the
  European Union's Seventh Framework Programme (FP7/2007-2013) under
  grant agreement n° 318633.
2014-11-07 16:38:14 -03:00
Heikki Linnakangas 2076db2aea Move the backup-block logic from XLogInsert to a new file, xloginsert.c.
xlog.c is huge, this makes it a little bit smaller, which is nice. Functions
related to putting together the WAL record are in xloginsert.c, and the
lower level stuff for managing WAL buffers and such are in xlog.c.

Also move the definition of XLogRecord to a separate header file. This
causes churn in the #includes of all the files that write WAL records, and
redo routines, but it avoids pulling in xlog.h into most places.

Reviewed by Michael Paquier, Alvaro Herrera, Andres Freund and Amit Kapila.
2014-11-06 13:55:36 +02:00
Bruce Momjian 171c377a0a C comment: mention why the Gregorian calendar is used pre-1582 2014-11-06 02:33:05 -05:00
Heikki Linnakangas 5028f22f6e Switch to CRC-32C in WAL and other places.
The old algorithm was found to not be the usual CRC-32 algorithm, used by
Ethernet et al. We were using a non-reflected lookup table with code meant
for a reflected lookup table. That's a strange combination that AFAICS does
not correspond to any bit-wise CRC calculation, which makes it difficult to
reason about its properties. Although it has worked well in practice, seems
safer to use a well-known algorithm.

Since we're changing the algorithm anyway, we might as well choose a
different polynomial. The Castagnoli polynomial has better error-correcting
properties than the traditional CRC-32 polynomial, even if we had
implemented it correctly. Another reason for picking that is that some new
CPUs have hardware support for calculating CRC-32C, but not CRC-32, let
alone our strange variant of it. This patch doesn't add any support for such
hardware, but a future patch could now do that.

The old algorithm is kept around for tsquery and pg_trgm, which use the
values in indexes that need to remain compatible so that pg_upgrade works.
While we're at it, share the old lookup table for CRC-32 calculation
between hstore, ltree and core. They all use the same table, so might as
well.
2014-11-04 11:39:48 +02:00
Heikki Linnakangas 404bc51cde Remove support for 64-bit CRC.
It hasn't been used for anything for a long time.
2014-11-04 11:33:08 +02:00
Robert Haas 2bd9e412f9 Support frontend-backend protocol communication using a shm_mq.
A background worker can use pq_redirect_to_shm_mq() to direct protocol
that would normally be sent to the frontend to a shm_mq so that another
process may read them.

The receiving process may use pq_parse_errornotice() to parse an
ErrorResponse or NoticeResponse from the background worker and, if
it wishes, ThrowErrorData() to propagate the error (with or without
further modification).

Patch by me.  Review by Andres Freund.
2014-10-31 12:02:40 -04:00
Robert Haas 6cb4afff33 Avoid setup work for invalidation messages at start-of-(sub)xact.
Instead of initializing a new TransInvalidationInfo for every
transaction or subtransaction, we can just do it for those
transactions or subtransactions that actually need to queue
invalidation messages.  That also avoids needing to free those
entries at the end of a transaction or subtransaction that does
not generate any invalidation messages, which is by far the
common case.

Patch by me.  Review by Simon Riggs and Andres Freund.
2014-10-29 12:35:19 -04:00
Tom Lane b2cbced9ee Support timezone abbreviations that sometimes change.
Up to now, PG has assumed that any given timezone abbreviation (such as
"EDT") represents a constant GMT offset in the usage of any particular
region; we had a way to configure what that offset was, but not for it
to be changeable over time.  But, as with most things horological, this
view of the world is too simplistic: there are numerous regions that have
at one time or another switched to a different GMT offset but kept using
the same timezone abbreviation.  Almost the entire Russian Federation did
that a few years ago, and later this month they're going to do it again.
And there are similar examples all over the world.

To cope with this, invent the notion of a "dynamic timezone abbreviation",
which is one that is referenced to a particular underlying timezone
(as defined in the IANA timezone database) and means whatever it currently
means in that zone.  For zones that use or have used daylight-savings time,
the standard and DST abbreviations continue to have the property that you
can specify standard or DST time and get that time offset whether or not
DST was theoretically in effect at the time.  However, the abbreviations
mean what they meant at the time in question (or most recently before that
time) rather than being absolutely fixed.

The standard abbreviation-list files have been changed to use this behavior
for abbreviations that have actually varied in meaning since 1970.  The
old simple-numeric definitions are kept for abbreviations that have not
changed, since they are a bit faster to resolve.

While this is clearly a new feature, it seems necessary to back-patch it
into all active branches, because otherwise use of Russian zone
abbreviations is going to become even more problematic than it already was.
This change supersedes the changes in commit 513d06ded et al to modify the
fixed meanings of the Russian abbreviations; since we've not shipped that
yet, this will avoid an undesirably incompatible (not to mention incorrect)
change in behavior for timestamps between 2011 and 2014.

This patch makes some cosmetic changes in ecpglib to keep its usage of
datetime lookup tables as similar as possible to the backend code, but
doesn't do anything about the increasingly obsolete set of timezone
abbreviation definitions that are hard-wired into ecpglib.  Whatever we
do about that will likely not be appropriate material for back-patching.
Also, a potential free() of a garbage pointer after an out-of-memory
failure in ecpglib has been fixed.

This patch also fixes pre-existing bugs in DetermineTimeZoneOffset() that
caused it to produce unexpected results near a timezone transition, if
both the "before" and "after" states are marked as standard time.  We'd
only ever thought about or tested transitions between standard and DST
time, but that's not what's happening when a zone simply redefines their
base GMT offset.

In passing, update the SGML documentation to refer to the Olson/zoneinfo/
zic timezone database as the "IANA" database, since it's now being
maintained under the auspices of IANA.
2014-10-16 15:22:10 -04:00
Alvaro Herrera 7b1c2a0f20 Split builtins.h to a new header ruleutils.h
The new header contains many prototypes for functions in ruleutils.c
that are not exposed to the SQL level.

Reviewed by Andres Freund and Michael Paquier.
2014-10-08 18:10:47 -03:00
Alvaro Herrera df630b0dd5 Implement SKIP LOCKED for row-level locks
This clause changes the behavior of SELECT locking clauses in the
presence of locked rows: instead of causing a process to block waiting
for the locks held by other processes (or raise an error, with NOWAIT),
SKIP LOCKED makes the new reader skip over such rows.  While this is not
appropriate behavior for general purposes, there are some cases in which
it is useful, such as queue-like tables.

Catalog version bumped because this patch changes the representation of
stored rules.

Reviewed by Craig Ringer (based on a previous attempt at an
implementation by Simon Riggs, who also provided input on the syntax
used in the current patch), David Rowley, and Álvaro Herrera.

Author: Thomas Munro
2014-10-07 17:23:34 -03:00
Stephen Frost c8a026e4f1 Revert 95d737ff to add 'ignore_nulls'
Per discussion, revert the commit which added 'ignore_nulls' to
row_to_json.  This capability would be better added as an independent
function rather than being bolted on to row_to_json.  Additionally,
the implementation didn't address complex JSON objects, and so was
incomplete anyway.

Pointed out by Tom and discussed with Andrew and Robert.
2014-09-29 13:32:22 -04:00