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and parsing work in PL/PgSQL: - memory management is now done via palloc(). The compiled representation of each function now has its own memory context. Therefore, the storage consumed by a function can be reclaimed via MemoryContextDelete(). During compilation, the CurrentMemoryContext is the function's memory context. This means that a palloc() is sufficient to allocate memory that will have the same lifetime as the function itself. As a result, code invoked during compilation should be careful to pfree() temporary allocations to avoid leaking memory. Since a lot of the code in the backend is not careful about releasing palloc'ed memory, that means we should switch into a temporary memory context before invoking backend functions. A temporary context appropriate for such allocations is `compile_tmp_cxt'. - The ability to use palloc() allows us to simply a lot of the code in the parser. Rather than representing lists of elements via ad hoc linked lists or arrays, we can use the List type. Rather than doing malloc followed by memset(0), we can just use palloc0(). - We now check that the user has supplied the right number of parameters to a RAISE statement. Supplying either too few or too many results in an error (at runtime). - PL/PgSQL's parser needs to accept arbitrary SQL statements. Since we do not want to duplicate the SQL grammar in the PL/PgSQL grammar, this means we need to be quite lax in what the PL/PgSQL grammar considers a "SQL statement". This can lead to misleading behavior if there is a syntax error in the function definition, since we assume a malformed PL/PgSQL construct is a SQL statement. Furthermore, these errors were only detected at runtime (when we tried to execute the alleged "SQL statement" via SPI). To rectify this, the patch changes the parser to invoke the main SQL parser when it sees a string it believes to be a SQL expression. This means that synctically-invalid SQL will be rejected during the compilation of the PL/PgSQL function. This is only done when compiling for "validation" purposes (i.e. at CREATE FUNCTION time), so it should not impose a runtime overhead. - Fixes for the various buffer overruns I've patched in stable branches in the past few weeks. I've rewritten code where I thought it was warranted (unlike the patches applied to older branches, which were minimally invasive). - Various other minor changes and cleanups. - Updates to the regression tests.
PostgreSQL Database Management System ===================================== This directory contains the source code distribution of the PostgreSQL database management system. PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings. The JDBC, ODBC, C++, Python, and Tcl interfaces have been moved to the PostgreSQL Projects Web Site at http://gborg.postgresql.org for separate maintenance. A Perl DBI/DBD driver is available from CPAN. See the file INSTALL for instructions on how to build and install PostgreSQL. That file also lists supported operating systems and hardware platforms and contains information regarding any other software packages that are required to build or run the PostgreSQL system. Changes between all PostgreSQL releases are recorded in the file HISTORY. Copyright and license information can be found in the file COPYRIGHT. A comprehensive documentation set is included in this distribution; it can be read as described in the installation instructions. The latest version of this software may be obtained at ftp://ftp.postgresql.org/pub/. For more information look at our web site located at http://www.postgresql.org/.