> * Auto-fill the free space map by scanning the buffer cache or by
> checking pages written by the background writer
< * Auto-fill the free space map by scanning the buffer cache or by
< checking pages written by the background writer
>
> * Create a bitmap of pages that need vacuuming
>
> Instead of sequentially scanning the entire table, have the background
> writer or some other process record pages that have expired rows, then
> VACUUM can look at just those pages rather than the entire table. In
> the event of a system crash, the bitmap would probably be invalidated.
< o Allow databases and schemas to be moved to different tablespaces
<
< One complexity is whether moving a schema should move all existing
< schema objects or just define the location for future object creation.
<
> o Allow databases to be moved to different tablespaces
484c480
< schema. Global system tables can never be moved.
> tablespace. Global system tables can never be moved.
< changes made by the interface driver for its internal use. One idea is
< for this to be a protocol-only feature. Another approach is to notify
< the protocol when a RESET CONNECTION command is used.
> changes made by the interface driver for its internal use. One idea
> is for this to be a protocol-only feature. Another approach is to
> notify the protocol when a RESET CONNECTION command is used.
< all temporary tables, removal of any NOTIFYs, cursors, prepared
< queries(?), currval()s, etc. This could be used for connection pooling.
< We could also change RESET ALL to have this functionality.
> temporary tables, removing any NOTIFYs, cursors, open transactions,
> prepared queries, currval()s, etc. This could be used for connection
> pooling. We could also change RESET ALL to have this functionality.
> The difficult of this features is allowing RESET ALL to not affect
> changes made by the interface driver for its internal use. One idea is
> for this to be a protocol-only feature. Another approach is to notify
> the protocol when a RESET CONNECTION command is used.
< cleaned up properly. A new signal is needed for safe termination.
> cleaned up properly. A new signal is needed for safe termination
> because backends must first do a query cancel, then exit once they
> have run the query cancel cleanup routine.
< logs
> logs [pitr]
130c130
< * Allow a warm standby system to also allow read-only queries
> * Allow a warm standby system to also allow read-only queries [pitr]
> * Allow pg_ctl to work properly with configuration files located outside
> the PGDATA directory
>
> pg_ctl can not read the pid file because it isn't located in the
> config directory but in the PGDATA directory. The solution is to
> allow pg_ctl to read and understand postgresql.conf to find the
> data_directory value.
>
< * Prevent child tables from altering constraints like CHECK that were
< inherited from the parent table
470a469,471
>
> o Prevent child tables from altering constraints like CHECK that were
> inherited from the parent table
<
< * Add XML output to pg_dump and COPY
<
< We already allow XML to be stored in the database, and XPath queries
< can be used on that data using /contrib/xml2. It also supports XSLT
< transformations.
> * Consider sorting hash buckets so entries can be found using a binary
> search, rather than a linear scan
> * In hash indexes, consider storing the hash value with or instead
> of the key itself
> * Add the features of packages
> o Make private objects accessable only to objects in the same schema
> o Allow current_schema.objname to access current schema objects
> o Add session variables
> o Allow nested schemas
<
< This will involve adding a way to respond to commit failure by either
< taking the server into offline/readonly mode or notifying the
< administrator
< * Add session start time and last statement time to pg_stat_activity
> * -Add session start time and last statement time to pg_stat_activity
134c134
< * Add the client IP address and port to pg_stat_activity
> * -Add the client IP address and port to pg_stat_activity
< Currently locale can only be set during initdb.
> Currently locale can only be set during initdb. No global tables have
> locale-aware columns. However, the database template used during
> database creation might have locale-aware indexes. The indexes would
> need to be reindexed to match the new locale.
> * Prevent to_char() on interval from returning meaningless values
>
> For example, to_char('1 month', 'mon') is meaningless. Basically,
> most date-related parameters to to_char() are meaningless for
> intervals because interval is not anchored to a date.
>
> * Allow to_char() on interval values to accumulate the highest unit
> requested
>
> o to_char(INTERVAL '1 hour 5 minutes', 'MI') => 65
> o to_char(INTERVAL '43 hours 20 minutes', 'MI' ) => 2600
> o to_char(INTERVAL '43 hours 20 minutes', 'WK:DD:HR:MI') => 0:1:19:20
> o to_char(INTERVAL '3 years 5 months','MM') => 41
>
> Some special format flag would be required to request such
> accumulation. Such functionality could also be added to EXTRACT.
> Prevent accumulation that crosses the month/day boundary because of
> the uneven number of days in a month.
>
< * Allow ORDER BY ... LIMIT 1 to select high/low value without sort or
> * Allow ORDER BY ... LIMIT # to select high/low value without sort or
868c868
< Right now, if no index exists, ORDER BY ... LIMIT 1 requires we sort
> Right now, if no index exists, ORDER BY ... LIMIT # requires we sort
870a871
> MIN/MAX already does this, but not for LIMIT > 1.
> * Allow ORDER BY ... LIMIT 1 to select high/low value without sort or
> index using a sequential scan for highest/lowest values
>
> Right now, if no index exists, ORDER BY ... LIMIT 1 requires we sort
> all values to return the high/low value. Instead The idea is to do a
> sequential scan to find the high/low value, thus avoiding the sort.
>
> One possible implementation is to start sequential scans from the lowest
> numbered buffer in the shared cache, and when reaching the end wrap
> around to the beginning, rather than always starting sequential scans
> at the start of the table.
< This allows vacuum to reclaim free space without requiring
< a sequential scan
> This allows vacuum to target specific pages for possible free space
> without requiring a sequential scan.
< * Consider parallel processing a single query
<
< This would involve using multiple threads or processes to do optimization,
< sorting, or execution of single query. The major advantage of such a
< feature would be to allow multiple CPUs to work together to process a
< single query.
<
< * Allow ORDER BY ... LIMIT 1 to select high/low value without sort or
< index using a sequential scan for highest/lowest values
<
< If only one value is needed, there is no need to sort the entire
< table. Instead a sequential scan could get the matching value.
<
< Solaris) might benefit from threading.
> Solaris) might benefit from threading. Also explore the idea of
> a single session using multiple threads to execute a query faster.
< Currently indexes do not have enough tuple tuple visibility
< information to allow data to be pulled from the index without
< also accessing the heap. One way to allow this is to set a bit
< to index tuples to indicate if a tuple is currently visible to
< all transactions when the first valid heap lookup happens. This
< bit would have to be cleared when a heap tuple is expired.
> Currently indexes do not have enough tuple visibility information
> to allow data to be pulled from the index without also accessing
> the heap. One way to allow this is to set a bit to index tuples
> to indicate if a tuple is currently visible to all transactions
> when the first valid heap lookup happens. This bit would have to
> be cleared when a heap tuple is expired.
< Bitmap indexes index single columns that can be combined with other bitmap
< indexes to dynamically create a composite index to match a specific query.
< Each index is a bitmap, and the bitmaps are bitwise AND'ed or OR'ed to be
< combined. They can index by tid or can be lossy requiring a scan of the
< heap page to find matching rows, or perhaps use a mixed solution where
< tids are recorded for pages with only a few matches and per-page bitmaps
< are used for more dense pages. Another idea is to use a 32-bit bitmap
< for every page and set a bit based on the item number mod(32).
> This feature allows separate indexes to be ANDed or ORed together. This
> is particularly useful for data warehousing applications that need to
> query the database in an many permutations. This feature scans an index
> and creates an in-memory bitmap, and allows that bitmap to be combined
> with other bitmap created in a similar way. The bitmap can either index
> all TIDs, or be lossy, meaning it records just page numbers and each
> page tuple has to be checked for validity in a separate pass.
< failure.
> failure. This could be triggered by a user command or a timer.
< * Force archiving of partially-full WAL files when pg_stop_backup() is
< called or the server is stopped
> * Automatically force archiving of partially-filled WAL files when
> pg_stop_backup() is called or the server is stopped
< * Add ANSI INTERVAL handling
> * Add ISo INTERVAL handling
< o Interpret syntax that isn't uniquely ANSI or PG, like '1:30' or
< '1' as ANSI syntax, e.g. interpret '1:30' MINUTE TO SECOND as
> o Interpret syntax that isn't uniquely ISO or PG, like '1:30' or
> '1' as ISO syntax, e.g. interpret '1:30' MINUTE TO SECOND as
649c649
< * Add pre-parsing phase that converts non-ANSI syntax to supported
> * Add pre-parsing phase that converts non-ISO syntax to supported
< o Process mixed ANSI/PG syntax, and round value to requested
< precision or generate an error
< o Interpret INTERVAL '1 year' MONTH as CAST (INTERVAL '1 year' AS
< INTERVAL MONTH), and this should return '12 months'
194a191,194
> o Interpret INTERVAL '1 year' MONTH as CAST (INTERVAL '1 year' AS
> INTERVAL MONTH), and this should return '12 months'
> o Round or truncate values to the requested precision, e.g.
> INTERVAL '11 months' AS YEAR should return one or zero
< o Add support for day-time syntax, INTERVAL '1 2:03:04'
> o Add support for day-time syntax, INTERVAL '1 2:03:04'
192c192,194
< o Interpret INTERVAL '1:30' MINUTE TO SECOND as '1 minute 30 seconds'
> o Interpret syntax that isn't uniquely ANSI or PG, like '1:30' or
> '1' as ANSI syntax, e.g. interpret '1:30' MINUTE TO SECOND as
> '1 minute 30 seconds'
< * Add support for ANSI time INTERVAL syntax, INTERVAL '1 2:03:04' DAY TO SECOND
< * Add support for ANSI date INTERVAL syntax, INTERVAL '20-6' YEAR TO MONTH
< * Process mixed ANSI/PG INTERVAL syntax, and round value to requested precision
<
< Interpret INTERVAL '1 year' MONTH as CAST (INTERVAL '1 year' AS INTERVAL
< MONTH), and this should return '12 months'
<
< * Interpret INTERVAL '1:30' MINUTE TO SECOND as '1 minute 30 seconds'
> * Add ANSI INTERVAL handling
> o Add support for day-time syntax, INTERVAL '1 2:03:04'
> DAY TO SECOND
> o Add support for year-month syntax, INTERVAL '50-6' YEAR TO MONTH
> o Process mixed ANSI/PG syntax, and round value to requested
> precision or generate an error
> o Interpret INTERVAL '1 year' MONTH as CAST (INTERVAL '1 year' AS
> INTERVAL MONTH), and this should return '12 months'
> o Interpret INTERVAL '1:30' MINUTE TO SECOND as '1 minute 30 seconds'
> o Support precision, CREATE TABLE foo (a INTERVAL MONTH(3))
< * Add support for ANSI date INTERVAL syntax, INTERVAL '9-3' YEAR TO MONTH
> * Add support for ANSI date INTERVAL syntax, INTERVAL '20-6' YEAR TO MONTH
< * Add support for ANSI date INTERVAL syntax, INTERVAL '1-2' YEAR TO MONTH
> * Add support for ANSI date INTERVAL syntax, INTERVAL '9-3' YEAR TO MONTH
> * Add support for ANSI time INTERVAL syntax, INTERVAL '1 2:03:04' DAY TO SECOND
> * Add support for ANSI date INTERVAL syntax, INTERVAL '1-2' YEAR TO MONTH
> * Process mixed ANSI/PG INTERVAL syntax, and round value to requested precision
184a188,189
> Interpret INTERVAL '1 year' MONTH as CAST (INTERVAL '1 year' AS INTERVAL
> MONTH), and this should return '12 months'
>
> * Support table partitioning that allows a single table to be stored
> in subtables that are partitioned based on the primary key or a WHERE
> clause
< SQL-spec compliant, so allow such handling to be disabled.
> SQL-spec compliant, so allow such handling to be disabled. However,
> disabling backslashes could break many third-party applications and tools.
< o Disallow encodings like UTF8 which PostgreSQL supports
< but the operating system does not (already disallowed by
< pginstaller)
> o Add support for Unicode
< To fix UTF8, the data needs to be converted to UTF16 and then
< the Win32 wcscoll() can be used, and perhaps other functions
> To fix this, the data needs to be converted to/from UTF16/UTF8
> so the Win32 wcscoll() can be used, and perhaps other functions
< locales but provides no ordering.
<
> locales but provides no ordering or character set classes.
< * Allow server configuration parameters to be remotely modified
> * Allow pg_hba.conf settings to be controlled via SQL
>
> This would require a new global table that is dumped to flat file for
> use by the postmaster. We do a similar thing for pg_shadow currently.
>
< * Consider use of open/fcntl(O_DIRECT) to minimize OS caching
> * Consider use of open/fcntl(O_DIRECT) to minimize OS caching,
> especially for WAL writes
the item:
< o Automatic failover
<
< The proper solution to this will probably the use of a master/slave
< replication solution like Sloney and a connection pooling tool like
< pgpool.
<
< all temporary tables, removal of any NOTIFYs, etc. This could be used
< for connection pooling. We could also change RESET ALL to have this
< functionality.
> all temporary tables, removal of any NOTIFYs, cursors, prepared
> queries(?), currval()s, etc. This could be used for connection pooling.
> We could also change RESET ALL to have this functionality.
< BY col {DESC} LIMIT 1. Completing this item involves making this
> BY col {DESC} LIMIT 1. Completing this item involves doing this
< invalidated if anyone modifies the table.
<
> invalidated if anyone modifies the table. Another idea is to
> get a count directly from a unique index, but for this to be
> faster than a sequential scan it must avoid access to the heap
> to obtain tuple visibility information.
>
> * Allow data to be pulled directly from indexes
>
> Currently indexes do not have enough tuple tuple visibility
> information to allow data to be pulled from the index without
> also accessing the heap. One way to allow this is to set a bit
> to index tuples to indicate if a tuple is currently visible to
> all transactions when the first valid heap lookup happens. This
> bit would have to be cleared when a heap tuple is expired.
>
< * Allow building with directories containing spaces
> * Allow building in directories containing spaces
< There are two capabilities here, first the ability to build from a
< source directory that contains spaces, and second the ability to install
< into a directory that contains spaces. The first is probably not
< possible because 'gmake' and other compiler tools do not fully support
< spaces in path names. The second is possible with proper quoting in
< the makefiles. Because PostgreSQL supports relocatable installs, it
< is possible to install into a directory that doesn't contain spaces and
< then copy the install to a directory with spaces.
> This is probably not possible because 'gmake' and other compiler tools
> do not fully support quoting of paths with spaces.
>
> * Allow installing to directories containing spaces
>
> This is possible if proper quoting is added to the makefiles for the
> install targets. Because PostgreSQL supports relocatable installs, it
> is already possible to install into a directory that doesn't contain
> spaces and then copy the install to a directory with spaces.
> There are two capabilities here, first the ability to build from a
> source directory that contains spaces, and second the ability to install
> into a directory that contains spaces. The first is probably not
> possible because 'gmake' and other compiler tools do not fully support
> spaces in path names. The second is possible with proper quoting in
> the makefiles. Because PostgreSQL supports relocatable installs, it
> is possible to install into a directory that doesn't contain spaces and
> then copy the install to a directory with spaces.
< o Disallow encodings like UTF8 which which PostgreSQL supports
> o Disallow encodings like UTF8 which PostgreSQL supports
914a915,917
>
> To fix UTF8, the data needs to be converted to UTF16 and then
> the Win32 strcoll() can be used.
> * Improve the background writer
>
> Allow the background writer to more efficiently write dirty buffers
> from the end of the LRU cache and use a clock sweep algorithm to
> write other dirty buffers to reduced checkpoint I/O
>
> * Allow the size of the buffer cache used by temporary objects to be
> specified as a GUC variable
>
> Larger local buffer cache sizes requires more efficient handling of
> local cache lookups.
< * Make log_min_duration_statement output when the duration is reached rather
< than when the statement completes
<
< This prints long queries while they are running, making trouble shooting
< easier. Also, it eliminates the need for log_statement because it
< would now be the same as a log_min_duration_statement of zero.
> * Make log_min_duration_statement output when the duration is reached rather
> than when the statement completes
>
> This prints long queries while they are running, making trouble shooting
> easier. Also, it eliminates the need for log_statement because it
> would now be the same as a log_min_duration_statement of zero.
9c5
< Last updated: Mon Nov 29 23:33:09 EST 2004
> Last updated: Tue Nov 30 00:03:37 EST 2004
13a10,16
> #A hyphen, "-", marks changes that will appear in the upcoming 8.1 release.#
>
> Bracketed items, "[]", have more detail.
>
> This list contains all known PostgreSQL bugs and feature requests. If
> you would like to work on an item, please read the developer's FAQ
> first.
> * Auto-vacuum
> o Move into the backend code
> o Scan the buffer cache to find free space or use background writer
> o Use free-space map information to guide refilling
< information, either by name or offset from UTC
> information, either zone name or offset from UTC
>
> If the TIMESTAMP value is stored with a time zone name, interval
> computations should adjust based on the time zone rules, e.g. adding
> 24 hours to a timestamp would yield a different result from adding one
> day.
>
< * Eliminate WAL logging for CREATE INDEX/REINDEX/CREATE TABLE AS when
< not doing WAL archiving
> * Eliminate WAL logging for CREATE TABLE AS when not doing WAL archiving
< * Allow GRANT/REVOKE permissions to be given to all schema objects with one
> * Allow GRANT/REVOKE permissions to be applied to all schema objects with one
60c60
< specifications. This is because new databases are created by copying
> specifications. This is because new databases are created by copying
63c63
< directory would create a new database with tables that had incorrect
> directory would create a new database with tables that had incorrect
72c72
<
>
85c85
< By not showing commented-out variables, we discourage people from
> By not showing commented-out variables, we discourage people from
91c91
< * Allow point-in-time recovery to archive partially filled write-ahead
> * Allow point-in-time recovery to archive partially filled write-ahead
102c102
< Currently all schemas are owned by the super-user because they are
> Currently all schemas are owned by the super-user because they are
128c128
< * Allow INET subnet tests with non-constants to be indexed
> * Allow INET subnet tests using non-constants to be indexed
143,144c143,144
< * Allow to_char to print localized month names
< * Allow functions to have a search path specified at creation time
> * Allow to_char() to print localized month names
> * Allow functions to have a schema search path specified at creation time
146c146
< * Add GUC variable to allow output of interval values in ISO8601 format
> * Add a GUC variable to allow output of interval values in ISO8601 format
154,155c154,155
< * Prevent inet cast to cidr if the unmasked bits are not zero, or
< zero bits
> * Prevent INET cast to CIDR if the unmasked bits are not zero, or
> zero the bits
158c158
< o Allow nulls in arrays
> o Allow NULLs in arrays
160,161c160,161
< o Delay resolution of array expression type so assignment coercion
< can be performed on empty array expressions
> o Delay resolution of array expression's data type so assignment
> coercion can be performed on empty array expressions
218,219c218,219
< key, foreign key [inheritance]
< * UNIQUE INDEX on base column not honored on inserts/updates from
> key, foreign key
> * UNIQUE INDEX on base column not honored on INSERTs/UPDATEs from
221c221
< (dup) should fail [inheritance]
> (dup) should fail
246c246
< * Fetch heap pages matching index entries in sequential order [performance]
> * Fetch heap pages matching index entries in sequential order
307c307
< functionality in DELETE. It's been agreed that the keyword should
> functionality in DELETE. It's been agreed that the keyword should
318c318
< * Allow PREPARE to automatically determine parameter types based on the SQL
> * Allow PREPARE to automatically determine parameter types based on the SQL
340,342d339
< * Allow CREATE TABLE foo (f1 INT CHECK (f1 > 0) CHECK (f1 < 10)) to work
< by searching for non-conflicting constraint names, and prefix with
< table name?
347c344
< new database.
> a new database.
350,351d346
< * Ignore temporary tables from other sessions when processing
< inheritance?
354,355c349,351
< * Add a session mode to warn about non-standard SQL usage in queries
< * Add MERGE command that does UPDATE/DELETE, or on failure, INSERT (rules, triggers?)
> * Add a GUC variable to warn about non-standard SQL usage in queries
> * Add MERGE command that does UPDATE/DELETE, or on failure, INSERT (rules,
> triggers?)
357,359c353,356
< * Add NOVICE output level for helpful messages like automatic sequence/index creation
< * Add COMMENT ON for all cluster global objects (users, groups,
< databases and tablespaces)
> * Add NOVICE output level for helpful messages like automatic sequence/index
> creation
> * Add COMMENT ON for all cluster global objects (users, groups, databases
> and tablespaces)
363c360
< When enabled, this would allow errors in multi-statement transactions
> When enabled, this would allow errors in multi-statement transactions
417c414
< o Allow COPY to optionally include column headings as the first line
> o Allow COPY to optionally include column headings in the first line
450c447
<
>
462c459
< o Handle references to temporary tables that are created, destroyed,
> o Handle references to temporary tables that are created, destroyed,
464c461
<
>
469d465
< o Improve PL/PgSQL exception handling using savepoints
488c484
<
>
503d498
<
518c513
< o Add pg_dumpall custom format dumps.
> o Add pg_dumpall custom format dumps.
520c515
< This is probably best done by combining pg_dump and pg_dumpall
> This is probably best done by combining pg_dump and pg_dumpall
532d526
< o Improve error handling (?)
555c549
< Adding shared locks requires recording the table/rows numbers in a
> Adding shared locks requires recording the table/rows numbers in a
643c637
< Posix_fadvise() can control both sequential/random file caching and
> Posix_fadvise() can control both sequential/random file caching and
703c697
< from distributted.net, http://www1.distributed.net/source,
> from distributted.net, http://www1.distributed.net/source,
729c723
< * Add connection pooling [pool]
> * Add connection pooling
755d748
<
759c752
<
>
768c761
< so an abrupt operating system restart might lose a few seconds of
> so an abrupt operating system restart might lose a few seconds of
785c778
< * Add utility to compute accurate random_page_cost value
> * Create utility to compute accurate random_page_cost value
787,789d779
< * Allow sorting, temp files, temp tables to use multiple work directories
<
< This allows the I/O load to be spread across multiple disk drives.
795a786
>
808,809c799,800
<
< * Use mmap() rather than SYSV shared memory or to write WAL files (?) [mmap]
>
> * Use mmap() rather than SYSV shared memory or to write WAL files (?)
812,813c803,804
< portability issues. Anonymous mmap (or mmap to /dev/zero) is required
< to prevent I/O overhead.
> portability issues. Anonymous mmap (or mmap to /dev/zero) is required
> to prevent I/O overhead.
817,819c808,810
< Doing I/O to large tables would consume a lot of address space or
< require frequent mapping/unmapping. Extending the file also causes
< mapping problems that might require mapping only individual pages,
> Doing I/O to large tables would consume a lot of address space or
> require frequent mapping/unmapping. Extending the file also causes
> mapping problems that might require mapping only individual pages,
821c812
< way to _prevent_ I/O to disk from the dirty shared buffers so changes
> way to _prevent_ I/O to disk from the dirty shared buffers so changes
826c817
< tuple overhead
> per-tuple overhead
829,831c820,822
< This would involve using multiple threads or processes to do optimization,
< sorting, or execution of single query. The major advantage of such a
< feature would be to allow multiple CPUs to work together to process a
> This would involve using multiple threads or processes to do optimization,
> sorting, or execution of single query. The major advantage of such a
> feature would be to allow multiple CPUs to work together to process a
834c825
< * Research the use of larger pages sizes
> * Research the use of larger page sizes
842a834
> * Move some /contrib modules out to their own project sites
845d836
< * Improve access-permissions check on data directory in Cygwin (Tom)
847,848c838
< * Clarify use of 'application' and 'command' tags in SGML docs
< * Better document ability to build only certain interfaces (Marc)
> * Improve documentation to build only interfaces (Marc)
852,853d841
< * Research interaction of setitimer() and sleep() used by statement_timeout
< * Rename /scripts directory because they are all C programs now
856,857d843
< * Allow binaries to be statically linked so they are more easily relocated
< * Move some /contrib modules out to their own project sites
862c848
< o Remove per-backend parameter file and move into shared memory?
> o Remove per-backend parameter file and move into shared memory
877,878c863,864
< o Update clients to use data types, typmod, schema.table.column names of
< result sets using new query protocol
> o Update clients to use data types, typmod, schema.table.column names
> of result sets using new query protocol
900d885
< * Kris is Kris Jurka
910c895
< * Simon is Simon Riggs
> * Simon is Simon Riggs <simon@2ndquadrant.com>
913d897
< * Teodor is
<
< * psql tab completion
<
< o Provide a list of conversions after ALTER CONVERSION?
< o Support for ALTER SEQUENCE clauses
< o Add RENAME TO to ALTER TRIGGER
< o Support for ALTER USER
< o Fix ALTER (GROUP|DOMAIN|...) <sth> DROP
< o Support for ALTER LANGUAGE <sth> RENAME TO
< o Improve support for COPY
< o Improve support for ALTER TABLE
< heap page to find matching rows.
> heap page to find matching rows, or perhaps use a mixed solution where
> tids are recorded for pages with only a few matches and per-page bitmaps
> are used for more dense pages. Another idea is to use a 32-bit bitmap
> for every page and set a bit based on the item number mod(32).
< Such indexes could be more compact if there are only a few unique values.
> Such indexes could be more compact if there are only a few distinct values.
> Such indexes can also be compressed. Keeping such indexes updated can be
> costly.
< portability issues. Anonymous mmap is required to prevent I/O
< overhead.
> portability issues. Anonymous mmap (or mmap to /dev/zero) is required
> to prevent I/O overhead.
>
> * Consider mmap()'ing files into a backend?
>
> Doing I/O to large tables would consume a lot of address space or
> require frequent mapping/unmapping. Extending the file also causes
> mapping problems that might require mapping only individual pages,
> leading to thousands of mappings. Another problem is that there is no
> way to _prevent_ I/O to disk from the dirty shared buffers so changes
> could hit disk before WAL is written.
< posix_fadvise() [fadvise]
> posix_fadvise()
>
> Posix_fadvise() can control both sequential/random file caching and
> free-behind behavior, but it is unclear how the setting affects other
> backends that also have the file open, and the feature is not supported
> on all operating systems.
>
< * CREATE TABLE AS can not determine column lengths from expressions [atttypmod]
> * Allow CREATE TABLE AS to determine column lengths for complex
> expressions like SELECT col1 || col2
< * Automatically create rules on views so they are updateable, per SQL99 [view]
> * Automatically create rules on views so they are updateable, per SQL99
>
> We can only auto-create rules for simple views. For more complex
> cases users will still have to write rules.
>
* Allow database recovery where tablespaces can't be created
When a pg_dump is restored, all tablespaces will attempt to be created
in their original locations. If this fails, the user must be able to
adjust the restore process.
< that can spam more than one table.
> that can span more than one table.
239c239
< rather than just col1
> rather than just col1; also called skip-scanning.
641c641,642
< * Add free-behind capability for large sequential scans [fadvise]
> * Allow free-behind capability for large sequential scans, perhaps using
> posix_fadvise() [fadvise]
< * Allow the creation of bitmap indexes which can be quickly combined
< with other bitmap indexes
> * Allow non-bitmap indexes to be combined by creating bitmaps in memory
259,261c258,259
< combined. Such indexes could be more compact if there are few unique
< value. Also, perhaps they can be lossy requiring a scan of the heap page
< to find matching rows.
> combined. They can index by tid or can be lossy requiring a scan of the
> heap page to find matching rows.
263c261,262
< * Allow non-bitmap indexes to be combined
> * Allow the creation of on-disk bitmap indexes which can be quickly
> combined with other bitmap indexes
265,266c264
< Do lookups on non-bitmap indexes and create bitmaps in memory that can be
< combined with other indexes.
> Such indexes could be more compact if there are few unique value.
< * Use bitmaps to combine existing indexes [performance]
> * Allow the creation of bitmap indexes which can be quickly combined
> with other bitmap indexes
255,257c256,266
< Bitmap indexes allow single indexed columns to be combined to
< dynamically create a composite index to match a specific query. Each
< index is a bitmap, and the bitmaps are AND'ed or OR'ed to be combined.
> Bitmap indexes index single columns that can be combined with other bitmap
> indexes to dynamically create a composite index to match a specific query.
> Each index is a bitmap, and the bitmaps are bitwise AND'ed or OR'ed to be
> combined. Such indexes could be more compact if there are few unique
> value. Also, perhaps they can be lossy requiring a scan of the heap page
> to find matching rows.
>
> * Allow non-bitmap indexes to be combined
>
> Do lookups on non-bitmap indexes and create bitmaps in memory that can be
> combined with other indexes.
< This perhaps should use a round-robin allocation system where several
< tablespaces are used in a cycle. The cycle pointer should be global.
> It could start with a random tablespace from a supplied list and cycle
> through the list.
< * Add a GUC variable to control the tablespace for temporary objects
> * Add a GUC variable to control the tablespace for temporary objects and
> sort files
>
> This perhaps should use a round-robin allocation system where several
> tablespaces are used in a cycle. The cycle pointer should be global.
>
Bruce Momjian