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- <!-- $PostgreSQL: pgsql/doc/src/sgml/release.sgml,v 1.516 2007/10/10 13:43:42 momjian Exp $ -->
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+ <!-- $PostgreSQL: pgsql/doc/src/sgml/release.sgml,v 1.517 2007/10/10 14:09:49 momjian Exp $ -->
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Typical markup:
@@ -48,16 +48,14 @@ do it for earlier branch release files.
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<title>Overview</title>
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<para>
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- This release adds major new capabilities to the
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- <productname>PostgreSQL</> database system, including:
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+ This release adds many improvements that were requested by users,
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including:
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<itemizedlist>
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<listitem>
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<para>
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- Full text search now fully integrated into the core database
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- system
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+ Full text search is now a built-in feature
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</para>
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</listitem>
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@@ -70,14 +68,13 @@ do it for earlier branch release files.
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<listitem>
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<para>
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- Enumerated ( enum) data types
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+ enum data types
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</para>
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</listitem>
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<listitem>
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<para>
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- Universally Unique Identifier (UUID) data type, similar to that
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- defined by RFC 4122
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+ UUID data type, similar to that defined by RFC 4122
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</para>
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</listitem>
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@@ -89,34 +86,32 @@ do it for earlier branch release files.
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<listitem>
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<para>
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- Control of whether <literal>NULL</>s sort first or last, using
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<literal>ORDER BY ... NULLS FIRST/LAST</>
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</para>
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</listitem>
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<listitem>
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<para>
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- Updatable cursors using <literal>UPDATE/DELETE WHERE CURRENT OF</>
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- <replaceable>cursor_name</>
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+ Updatable cursors
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+ (<literal>UPDATE/DELETE WHERE CURRENT OF</>
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+ <replaceable>cursor_name</>)
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</para>
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</listitem>
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<listitem>
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<para>
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- Per-function server configuration parameter settings
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+ Per-function parameter settings
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</para>
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</listitem>
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<listitem>
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<para>
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- User-defined types can now have type modifiers
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+ User-defined types can now have type modifiers (parameters)
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</para>
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<para>
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- This allows a user type to take an optional modifier when
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- being created, e.g. <type>SSNUM(7)</>. Previously only
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- predefined system data types would allow this, e.g.
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- <type>CHAR(4)</>.
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+ Declarations such as <type>varchar(42)</type> are no longer
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+ restricted to use by built-in data types.
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</para>
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</listitem>
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@@ -133,10 +128,10 @@ do it for earlier branch release files.
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<listitem>
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<para>
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- Numerous improvements in logging and statistics collection,
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- including the ability to emit postmaster log messages in
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- <acronym> CSV</> format, which can be loaded into a database
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- table for analysis
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+ Numerous improvements in logging and statistics collection
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+ capabilities, including the ability to emit postmaster log messages
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+ in CSV format that can be directly loaded into a database table
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+ for analysis
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</para>
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</listitem>
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</para>
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<para>
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- This allows multiple vacuums to run concurrently, meaning
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- vacuuming of a large table will not prevent smaller tables from
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- being vacuumed at the same time. Autovacuum is now considered
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- mature and therefore is enabled by default.
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+ Autovacuum is now considered mature enough to be enabled by default.
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</para>
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</listitem>
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<listitem>
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<para>
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- The backend database server can now be compiled with
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- <productname> Microsoft Visual C++</>
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+ The entire <productname>PostgreSQL</productname> system can
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+ now be compiled with Microsoft Visual C++
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</para>
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<para>
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- Windows executables made with Visual C++ might have better
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- stability and performance than those made with other tool sets.
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- Development and debugging tools familiar to Windows developers
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- will also work .
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+ This will improve the ability of Windows-based developers to
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+ contribute to the project. Windows executables made with Visual C++
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+ may also have better stability and performance than those made with
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+ other tool sets .
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</para>
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</listitem>
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@@ -181,41 +173,32 @@ do it for earlier branch release files.
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<listitem>
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<para>
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- Asynchronous commit option allows transactions to be committed
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- but on-disk change to be delayed
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+ Asynchronous commit option to allow transactions to be reported
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+ committed before they have actually been flushed to disk
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</para>
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<para>
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- This feature dramatically increases performance for data
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- modification queries. The disadvantage is that because on-disk
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- changes are delayed, if the operating system crashes before data
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- is written to the disk, committed data will be lost. This is
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- only useful for applications that can accept some data loss.
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- Unlike <varname>fsync</varname>, asynchronous commit does not
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- risk database corruption; the worst case is that after an
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- operating system crash, the last few reportedly-committed
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- transactions will be missing.
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+ This would not, of course, be acceptable if the client takes some
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+ critical external action on the assumption that the transaction
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+ will be remembered; but for certain applications, it is an acceptable
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+ risk for some or all transactions to use this mode. Unlike existing
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+ options such as <varname>fsync</varname>, asynchronous commit does
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+ not risk database corruption; the worst case is that after a crash,
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+ the last few reportedly-committed transactions will not have
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+ taken effect.
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</para>
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</listitem>
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<listitem>
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<para>
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- <quote>Distributed</> checkpoints prevent I/O spikes during
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- checkpoints
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+ <quote>Distributed</> checkpoints to spread out the I/O load of a
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+ checkpoint
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</para>
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</listitem>
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<listitem>
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<para>
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- Heap-Only Tuples (<acronym>HOT</>) reduce overhead of updates
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- </para>
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-
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- <para>
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- To allow high concurrency <productname>PostgreSQL</> retains old
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- versions of updated rows. Previously only <command>VACUUM</>
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- could reuse space taken by dead rows. With <acronym>HOT</> dead
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- row space can be reused at the time of <command>UPDATE</> or
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- <command>INSERT</>. This allows for more consistent performance.
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+ Heap-Only Tuples (HOT) to reduce overhead of updates
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</para>
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</listitem>
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@@ -224,21 +207,12 @@ do it for earlier branch release files.
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Just-in-time background writer strategy to improve disk write
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efficiency
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</para>
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-
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- <para>
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- This basically makes the background writer self-tuning.
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- </para>
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-
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</listitem>
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<listitem>
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<para>
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- Reduction of both per-field and per-row storage requirements
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- </para>
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-
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- <para>
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- For example, two <type>CHAR(1)</type> fields now take 4 bytes
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- instead of 16.
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+ Reduction of on-disk data size through reducing both per-tuple
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+ and per-field overheads
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</para>
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</listitem>
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