< * Allow limits on per-db/user connections
> * Allow limits on per-db/role connections
< * Prevent default re-use of sysids for dropped users and roles
<
< Currently, if a user is removed while he still owns objects, a new
< user given might be given their user id and inherit the
< previous users objects.
<
450c444
< * Add COMMENT ON for all cluster global objects (users, roles, databases
> * Add COMMENT ON for all cluster global objects (roles, databases
609c603
< users and roles with separate DROP commands
> roles with separate DROP commands
< * Prevent default re-use of sysids for dropped users and groups
> * Prevent default re-use of sysids for dropped users and roles
450c450
< * Add COMMENT ON for all cluster global objects (users, groups, databases
> * Add COMMENT ON for all cluster global objects (users, roles, databases
609c609
< users and groups with separate DROP commands
> users and roles with separate DROP commands
> * Add NUMERIC division operator that doesn't round?
>
> Currently NUMERIC _rounds_ the result to the specified precision.
> This means division can return a result that multiplied by the
> divisor is greater than the dividend, e.g. this returns a value > 10:
>
> SELECT (10::numeric(2,0) / 6::numeric(2,0))::numeric(2,0) * 6;
>
> The positive modulus result returned by NUMERICs might be considered
> inaccurate, in one sense.
>
< * Allow administrators to safely terminate individual sessions
<
< Right now, SIGTERM will terminate a session, but it is treated as
< though the postmaster has paniced and shared memory might not be
< 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.
<
> * Allow administrators to safely terminate individual sessions either
> via an SQL function or SIGTERM
> * 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
Bruce Momjian