提交 ef110c0a 编写于 作者: B Bruce Momjian

Update HISTORY

上级 658b58dc
...@@ -46,7 +46,7 @@ ...@@ -46,7 +46,7 @@
Function-inlining for simple SQL functions Function-inlining for simple SQL functions
Simple SQL functions can now be inlined by including their SQL Simple SQL functions can now be inlined by including their SQL
in the main query. This improves performance by eliminating in the main query. This improves performance by eliminating
per-call overhead. That means, simple SQL functions now behave per-call overhead. That means simple SQL functions now behave
like macros. like macros.
Full support for IPv6 connections and IPv6 address data types Full support for IPv6 connections and IPv6 address data types
...@@ -58,11 +58,11 @@ ...@@ -58,11 +58,11 @@
Several people very familiar with the SSL API have overhauled Several people very familiar with the SSL API have overhauled
our SSL code to improve SSL key negotiation and error recovery. our SSL code to improve SSL key negotiation and error recovery.
Make free space map to efficiently reuse empty index pages, and other Make free space map efficiently reuse empty index pages, and other
free space management improvements free space management improvements
In previous releases, B-tree index pages that were left empty In previous releases, B-tree index pages that were left empty
because of deleted rows could only be reused by rows with index because of deleted rows could only be reused by rows with index
values similar to the original rows indexed on that page. In values similar to the rows originally indexed on that page. In
7.4, "VACUUM" records empty index pages and allows them to be 7.4, "VACUUM" records empty index pages and allows them to be
reused for any future index rows. reused for any future index rows.
...@@ -71,12 +71,12 @@ ...@@ -71,12 +71,12 @@
to access information about the schema objects defined in a to access information about the schema objects defined in a
database. database.
Cursors conform more closely with the SQL standard Cursors conform more closely to the SQL standard
The commands "FETCH" and "MOVE" have been overhauled to conform The commands "FETCH" and "MOVE" have been overhauled to conform
more closely to the SQL standard. more closely to the SQL standard.
Cursors can exist outside transactions Cursors can exist outside transactions
These cursors are also called holdable cursors These cursors are also called holdable cursors.
New client-to-server protocol New client-to-server protocol
The new protocol adds error codes, more status information, The new protocol adds error codes, more status information,
...@@ -124,7 +124,7 @@ ...@@ -124,7 +124,7 @@
Significant effort was invested to make the messages more Significant effort was invested to make the messages more
consistent and user-oriented. If your applications try to detect consistent and user-oriented. If your applications try to detect
different error conditions by parsing the error message, you are different error conditions by parsing the error message, you are
strongly encourage to use the new error code facility. strongly encouraged to use the new error code facility instead.
* Inner joins using the explicit JOIN syntax may behave differently * Inner joins using the explicit JOIN syntax may behave differently
because they are now better optimized. because they are now better optimized.
* A number of server configuration parameters have been renamed for * A number of server configuration parameters have been renamed for
...@@ -238,8 +238,8 @@ Performance Improvements ...@@ -238,8 +238,8 @@ Performance Improvements
of function-allocated memory when the function call completes, of function-allocated memory when the function call completes,
reducing the total memory used by functions. reducing the total memory used by functions.
* Improve GEQO optimizer performance (Tom) * Improve GEQO optimizer performance (Tom)
There were several inefficiencies in the way the GEQO optimizer This release fixes several inefficiencies in the way the GEQO
managed potential query paths. This release fixes this. optimizer manages potential query paths.
* Allow IN/NOT IN to be handled via hash tables (Tom) * Allow IN/NOT IN to be handled via hash tables (Tom)
* Improve NOT IN (subquery) performance (Tom) * Improve NOT IN (subquery) performance (Tom)
* Allow most IN subqueries to be processed as joins (Tom) * Allow most IN subqueries to be processed as joins (Tom)
...@@ -430,8 +430,9 @@ Utility Command Changes ...@@ -430,8 +430,9 @@ Utility Command Changes
deleted on transaction commit. deleted on transaction commit.
* Allow cursors outside transactions using WITH HOLD (Neil) * Allow cursors outside transactions using WITH HOLD (Neil)
In previous releases, cursors were removed at the end of the In previous releases, cursors were removed at the end of the
transaction. Using WITH HOLD, the current release allows cursors transaction that created them. Cursors can now be created with the
to remain readable after the creating transaction. WITH HOLD option, which allows them to continue to be accessed
after the creating transaction has committed.
* FETCH 0 and MOVE 0 now do nothing (Bruce) * FETCH 0 and MOVE 0 now do nothing (Bruce)
In previous releases, FETCH 0 fetched all remaining rows, and MOVE In previous releases, FETCH 0 fetched all remaining rows, and MOVE
0 moved to the end of the cursor. 0 moved to the end of the cursor.
...@@ -441,10 +442,12 @@ Utility Command Changes ...@@ -441,10 +442,12 @@ Utility Command Changes
In prior releases, the row count returned by "FETCH" and "MOVE" In prior releases, the row count returned by "FETCH" and "MOVE"
did not accurately reflect the number of rows processed. did not accurately reflect the number of rows processed.
* Properly handle SCROLL with cursors, or report an error (Neil) * Properly handle SCROLL with cursors, or report an error (Neil)
Certain cursors can not be fetched backwards optimally. By Allowing random access (both forward and backward scrolling) to
specifying SCROLL, extra work will be performed to guarantee that some kinds of queries cannot be done without some additional work.
the cursor can be fetched in reverse or random order. If SCROLL is specified when the cursor is created, this additional
* Implement SQL-compatible option FIRST, LAST, ABSOLUTE n, RELATIVE work will be performed. Furthermore, if the cursor has been
created with NO SCROLL, no random access is allowed.
* Implement SQL-compatible options FIRST, LAST, ABSOLUTE n, RELATIVE
n for "FETCH" and "MOVE" (Tom) n for "FETCH" and "MOVE" (Tom)
* Allow "EXPLAIN" on "DECLARE CURSOR" (Tom) * Allow "EXPLAIN" on "DECLARE CURSOR" (Tom)
* Allow "CLUSTER" to use index marked as pre-clustered by default * Allow "CLUSTER" to use index marked as pre-clustered by default
...@@ -460,8 +463,9 @@ Utility Command Changes ...@@ -460,8 +463,9 @@ Utility Command Changes
* Recover from "COPY" failure cleanly (Tom) * Recover from "COPY" failure cleanly (Tom)
* Prevent possible memory leaks in "COPY" (Tom) * Prevent possible memory leaks in "COPY" (Tom)
* Make "TRUNCATE" transaction-safe (Rod) * Make "TRUNCATE" transaction-safe (Rod)
"TRUNCATE" can now be used inside a transaction, and rolled back "TRUNCATE" can now be used inside a transaction. If the
if the transaction aborts. transaction aborts, the changes made by the "TRUNCATE" are
automatically rolled back.
* Allow prepare/bind of utility commands like "FETCH" and "EXPLAIN" * Allow prepare/bind of utility commands like "FETCH" and "EXPLAIN"
(Tom) (Tom)
* Add "EXPLAIN EXECUTE" (Neil) * Add "EXPLAIN EXECUTE" (Neil)
...@@ -758,8 +762,8 @@ Contrib Changes ...@@ -758,8 +762,8 @@ Contrib Changes
* Fix bug in metaphone() in fuzzystrmatch * Fix bug in metaphone() in fuzzystrmatch
* Improve adddepend (Rod) * Improve adddepend (Rod)
* Update spi/timetravel (Böjthe Zoltán) * Update spi/timetravel (Böjthe Zoltán)
* Fix dbase "-s" option and improve non-ASCII handling (Thomas * Fix dbase "-s" option and improve non-ASCII handling (Thomas Behr,
Behr, Márcio Smiderle) Márcio Smiderle)
* Remove array module because features now included by default (Joe) * Remove array module because features now included by default (Joe)
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