changes.tcl

轻量级数据库软件,嵌入式设计可以考虑考虑,性能不错

#
# Run this script to generated a changes.html output file
#
source common.tcl
header {SQLite changes}
puts {
<p>
This page provides a high-level summary of changes to SQLite.
For more detail, refer the the checkin logs generated by
CVS at
<a href="http://www.sqlite.org/cvstrac/timeline">
http://www.sqlite.org/cvstrac/timeline</a>.
</p>

<DL>
}


proc chng {date desc} {
  if {[regexp {\(([0-9.]+)\)} $date all vers]} {
    set label [string map {. _} $vers]
    puts "<A NAME=\"version_$label\">"
  }
  puts "<DT><B>$date</B></DT>"
  puts "<DD><P><UL>$desc</UL></P></DD>"
}

chng {2007 January 27 (3.3.12)} {
<li>Fix another bug in the IS NULL optimization that was added in
version 3.3.9.</li>
<li>Fix a assertion fault that occurred on deeply nested views.</li>
<li>Limit the amount of output that
<a href="pragma.html#pragma_integrity_check">PRAGMA integrity_check</a>
generates.</li>
<li>Minor syntactic changes to support a wider variety of compilers.</li>
}

chng {2007 January 22 (3.3.11)} {
<li>Fix another bug in the implementation of the new 
<a href="capi3ref.html#sqlite3_prepare_v2">sqlite3_prepare_v2()</a> API.
We'll get it right eventually...</li>
<li>Fix a bug in the IS NULL optimization that was added in version 3.3.9 -
the bug was causing incorrect results on certain LEFT JOINs that included
in the WHERE clause an IS NULL constraint for the right table of the
LEFT JOIN.</li>
<li>Make AreFileApisANSI() a no-op macro in winCE since winCE does not
support this function.</li>
}

chng {2007 January 9 (3.3.10)} {
<li>Fix bugs in the implementation of the new 
<a href="capi3ref.html#sqlite3_prepare_v2">sqlite3_prepare_v2()</a> API
that can lead to segfaults.</li>
<li>Fix 1-second round-off errors in the 
<a href="http://www.sqlite.org/cvstrac/wiki?p=DateAndTimeFunctions">
strftime()</a> function</li>
<li>Enhance the windows OS layer to provide detailed error codes</li>
<li>Work around a win2k problem so that SQLite can use single-character
database file names</li>
<li>The
<a href="pragma.html#pragma_user_version">user_version</a> and
<a href="pragma.html#pragma_schema_version">schema_version</a> pragmas 
correctly set their column names in the result set</li>
<li>Documentation updates</li>
}

chng {2007 January 4 (3.3.9)} {
<li>Fix bugs in pager.c that could lead to database corruption if two
processes both try to recover a hot journal at the same instant</li>
<li>Added the <a href="capi3ref.html#sqlite3_prepare_v2">sqlite3_prepare_v2()</a>
API.</li>
<li>Fixed the ".dump" command in the command-line shell to show
indices, triggers and views again.</li>
<li>Change the table_info pragma so that it returns NULL for the default
value if there is no default value</li>
<li>Support for non-ASCII characters in win95 filenames</li>
<li>Query optimizer enhancements:
<ul>
<li>Optimizer does a better job of using indices to satisfy ORDER BY
clauses that sort on the integer primary key</li>
<li>Use an index to satisfy an IS NULL operator in the WHERE clause</li>
<li>Fix a bug that was causing the optimizer to miss an OR optimization
opportunity</li>
<li>The optimizer has more freedom to reorder tables in the FROM clause
even in there are LEFT joins.</li>
</ul>
<li>Extension loading supported added to winCE</li>
<li>Allow constraint names on the DEFAULT clause in a table definition</li>
<li>Added the ".bail" command to the command-line shell</li>
<li>Make CSV (comma separate value) output from the command-line shell
more closely aligned to accepted practice</li>
<li>Experimental FTS2 module added</li>
<li>Use sqlite3_mprintf() instead of strdup() to avoid libc dependencies</li>
<li>VACUUM uses a temporary file in the official TEMP folder, not in the
same directory as the original database</li>
<li>The prefix on temporary filenames on windows is changed from "sqlite"
to "etilqs".</li>
}

chng {2006 October 9 (3.3.8)} {
<li>Support for full text search using the
<a href="http://www.sqlite.org/cvstrac/wiki?p=FullTextIndex">FTS1 module</a>
(beta)</li>
<li>Added OS-X locking patches (beta - disabled by default)</li>
<li>Introduce extended error codes and add error codes for various
kinds of I/O errors.</li>
<li>Added support for IF EXISTS on CREATE/DROP TRIGGER/VIEW</li>
<li>Fix the regression test suite so that it works with Tcl8.5</li>
<li>Enhance sqlite3_set_authorizer() to provide notification of calls to
    SQL functions.</li>
<li>Added experimental API:  sqlite3_auto_extension()</li>
<li>Various minor bug fixes</li>
}

chng {2006 August 12 (3.3.7)} {
<li>Added support for
<a href="http://www.sqlite.org/cvstrac/wiki?p=VirtualTables">virtual tables</a>
(beta)</li>
<li>Added support for 
<a href="http://www.sqlite.org/cvstrac/wiki?p=LoadableExtensions">
dynamically loaded extensions</a> (beta)</li>
<li>The 
<a href="capi3ref.html#sqlite3_interrupt">sqlite3_interrupt()</a>
routine can be called for a different thread</li>
<li>Added the <a href="lang_expr.html#match">MATCH</a> operator.</li>
<li>The default file format is now 1.  
}

chng {2006 June 6 (3.3.6)} {
<li>Plays better with virus scanners on windows</li>
<li>Faster :memory: databases</li>
<li>Fix an obscure segfault in UTF-8 to UTF-16 conversions</li>
<li>Added driver for OS/2</li>
<li>Correct column meta-information returned for aggregate queries</li>
<li>Enhanced output from EXPLAIN QUERY PLAN</li>
<li>LIMIT 0 now works on subqueries</li>
<li>Bug fixes and performance enhancements in the query optimizer</li>
<li>Correctly handle NULL filenames in ATTACH and DETACH</li>
<li>Inproved syntax error messages in the parser</li>
<li>Fix type coercion rules for the IN operator</li>
}

chng {2006 April 5 (3.3.5)} {
<li>CHECK constraints use conflict resolution algorithms correctly.</li>
<li>The SUM() function throws an error on integer overflow.</li>
<li>Choose the column names in a compound query from the left-most SELECT
    instead of the right-most.</li>
<li>The sqlite3_create_collation() function
    honors the SQLITE_UTF16_ALIGNED flag.</li>
<li>SQLITE_SECURE_DELETE compile-time option causes deletes to overwrite
    old data with zeros.</li>
<li>Detect integer overflow in abs().</li>
<li>The random() function provides 64 bits of randomness instead of
    only 32 bits.</li>
<li>Parser detects and reports automaton stack overflow.</li>
<li>Change the round() function to return REAL instead of TEXT.</li>
<li>Allow WHERE clause terms on the left table of a LEFT OUTER JOIN to
    contain aggregate subqueries.</li>
<li>Skip over leading spaces in text to numeric conversions.</li>
<li>Various minor bug and documentation typo fixes and
    performance enhancements.</li>
}

chng {2006 February 11 (3.3.4)} {
<li>Fix a blunder in the Unix mutex implementation that can lead to
deadlock on multithreaded systems.</li>
<li>Fix an alignment problem on 64-bit machines</li>
<li>Added the fullfsync pragma.</li>
<li>Fix an optimizer bug that could have caused some unusual LEFT OUTER JOINs
to give incorrect results.</li>
<li>The SUM function detects integer overflow and converts to accumulating
an approximate result using floating point numbers</li>
<li>Host parameter names can begin with '@' for compatibility with SQL Server.
</li>
<li>Other miscellaneous bug fixes</li>
}

chng {2006 January 31 (3.3.3)} {
<li>Removed support for an ON CONFLICT clause on CREATE INDEX - it never
worked correctly so this should not present any backward compatibility
problems.</li>
<li>Authorizer callback now notified of ALTER TABLE ADD COLUMN commands</li>
<li>After any changes to the TEMP database schema, all prepared statements
are invalidated and must be recreated using a new call to
sqlite3_prepare()</li>
<li>Other minor bug fixes in preparation for the first stable release
of version 3.3</li>
}

chng {2006 January 24 (3.3.2 beta)} {
<li>Bug fixes and speed improvements.  Improved test coverage.</li>
<li>Changes to the OS-layer interface: mutexes must now be recursive.</li>
<li>Discontinue the use of thread-specific data for out-of-memory
exception handling</li>
}

chng {2006 January 16 (3.3.1 alpha)} {
<li>Countless bug fixes</li>
<li>Speed improvements</li>
<li>Database connections can now be used by multiple threads, not just
the thread in which they were created.</li>
}

chng {2006 January 10 (3.3.0 alpha)} {
<li>CHECK constraints</li>
<li>IF EXISTS and IF NOT EXISTS clauses on CREATE/DROP TABLE/INDEX.</li>
<li>DESC indices</li>
<li>More efficient encoding of boolean values resulting in smaller database
files</li>
<li>More aggressive SQLITE_OMIT_FLOATING_POINT</li>
<li>Separate INTEGER and REAL affinity</li>
<li>Added a virtual function layer for the OS interface</li>
<li>"exists" method added to the TCL interface</li>
<li>Improved response to out-of-memory errors</li>
<li>Database cache can be optionally shared between connections
in the same thread</li>
<li>Optional READ UNCOMMITTED isolation (instead of the default
isolation level of SERIALIZABLE) and table level locking when
database connections share a common cache.</li>
}

chng {2005 December 19 (3.2.8)} {
<li>Fix an obscure bug that can cause database corruption under the
following unusual circumstances: A large INSERT or UPDATE statement which 
is part of an even larger transaction fails due to a uniqueness contraint
but the containing transaction commits.</li>
}

chng {2005 December 19 (2.8.17)} {
<li>Fix an obscure bug that can cause database corruption under the
following unusual circumstances: A large INSERT or UPDATE statement which 
is part of an even larger transaction fails due to a uniqueness contraint
but the containing transaction commits.</li>
}

chng {2005 September 24 (3.2.7)} {
<li>GROUP BY now considers NULLs to be equal again, as it should
</li>
<li>Now compiles on Solaris and OpenBSD and other Unix variants
that lack the fdatasync() function</li>
<li>Now compiles on MSVC++6 again</li>
<li>Fix uninitialized variables causing malfunctions for various obscure
queries</li>
<li>Correctly compute a LEFT OUTER JOINs that is constrained on the
left table only</li>
}

chng {2005 September 17 (3.2.6)} {
<li>Fix a bug that can cause database corruption if a VACUUM (or
    autovacuum) fails and is rolled back on a database that is
    larger than 1GiB</li>
<li>LIKE optiization now works for columns with COLLATE NOCASE</li>
<li>ORDER BY and GROUP BY now use bounded memory</li>
<li>Added support for COUNT(DISTINCT expr)</li>
<li>Change the way SUM() handles NULL values in order to comply with
    the SQL standard</li>
<li>Use fdatasync() instead of fsync() where possible in order to speed
    up commits slightly</li>
<li>Use of the CROSS keyword in a join turns off the table reordering
    optimization</li>
<li>Added the experimental and undocumented EXPLAIN QUERY PLAN capability</li>
<li>Use the unicode API in windows</li>
}

chng {2005 August 27 (3.2.5)} {
<li>Fix a bug effecting DELETE and UPDATE statements that changed
more than 40960 rows.</li>
<li>Change the makefile so that it no longer requires GNUmake extensions</li>
<li>Fix the --enable-threadsafe option on the configure script</li>
<li>Fix a code generator bug that occurs when the left-hand side of an IN
operator is constant and the right-hand side is a SELECT statement</li>
<li>The PRAGMA synchronous=off statement now disables syncing of the
master journal file in addition to the normal rollback journals</li>
}

chng {2005 August 24 (3.2.4)} {
<li>Fix a bug introduced in the previous release
that can cause a segfault while generating code
for complex WHERE clauses.</li>
<li>Allow floating point literals to begin or end with a decimal point.</li>
}

chng {2005 August 21 (3.2.3)} {
<li>Added support for the CAST operator</li>
<li>Tcl interface allows BLOB values to be transferred to user-defined
functions</li>
<li>Added the "transaction" method to the Tcl interface</li>
<li>Allow the DEFAULT value of a column to call functions that have constant
operands</li>
<li>Added the ANALYZE command for gathering statistics on indices and
using those statistics when picking an index in the optimizer</li>
<li>Remove the limit (formerly 100) on the number of terms in the
WHERE clause</li>
<li>The right-hand side of the IN operator can now be a list of expressions
instead of just a list of constants</li>
<li>Rework the optimizer so that it is able to make better use of indices</li>
<li>The order of tables in a join is adjusted automatically to make
better use of indices</li>
<li>The IN operator is now a candidate for optimization even if the left-hand
side is not the left-most term of the index.  Multiple IN operators can be
used with the same index.</li>
<li>WHERE clause expressions using BETWEEN and OR are now candidates
for optimization</li>
<li>Added the "case_sensitive_like" pragma and the SQLITE_CASE_SENSITIVE_LIKE
compile-time option to set its default value to "on".</li>
<li>Use indices to help with GLOB expressions and LIKE expressions too
when the case_sensitive_like pragma is enabled</li>
<li>Added support for grave-accent quoting for compatibility with MySQL</li>
<li>Improved test coverage</li>
<li>Dozens of minor bug fixes</li>
}

chng {2005 June 13 (3.2.2)} {
<li>Added the sqlite3_db_handle() API</li>
<li>Added the sqlite3_get_autocommit() API</li>
<li>Added a REGEXP operator to the parser.  There is no function to back
up this operator in the standard build but users can add their own using
sqlite3_create_function()</li>