## E.355. Release 6.1

Release date: 1997-06-08

The regression tests have been adapted and extensively modified for the 6.1 release of PostgreSQL.

Three new data types (`datetime`, `timespan`, and `circle`) have been added to the native set of PostgreSQL types. Points, boxes, paths, and polygons have had their output formats made consistent across the data types. The polygon output in misc.out has only been spot-checked for correctness relative to the original regression output.

PostgreSQL 6.1 introduces a new, alternate optimizer which uses genetic algorithms. These algorithms introduce a random behavior in the ordering of query results when the query contains multiple qualifiers or multiple tables (giving the optimizer a choice on order of evaluation). Several regression tests have been modified to explicitly order the results, and hence are insensitive to optimizer choices. A few regression tests are for data types which are inherently unordered (e.g. points and time intervals) and tests involving those types are explicitly bracketed with `set geqo to 'off'` and `reset geqo`.

The interpretation of array specifiers (the curly braces around atomic values) appears to have changed sometime after the original regression tests were generated. The current `./expected/*.out` files reflect this new interpretation, which might not be correct!

The float8 regression test fails on at least some platforms. This is due to differences in implementations of `pow()` and `exp()` and the signaling mechanisms used for overflow and underflow conditions.

The “random” results in the random test should cause the “random” test to be “failed”, since the regression tests are evaluated using a simple diff. However, “random” does not seem to produce random results on my test machine (Linux/gcc/i686).

### E.355.1. Migration to Version 6.1

This migration requires a complete dump of the 6.0 database and a restore of the database in 6.1.

Those migrating from earlier 1.* releases should first upgrade to 1.09 because the COPY output format was improved from the 1.02 release.

### E.355.2. Changes

    Bug Fixes
    ---------
    packet length checking in library routines
    lock manager priority patch
    check for under/over flow of float8(Bruce)
    multitable join fix(Vadim)
    SIGPIPE crash fix(Darren)
    large object fixes(Sven)
    allow btree indexes to handle NULLs(Vadim)
    timezone fixes(D'Arcy)
    select SUM(x) can return NULL on no rows(Thomas)
    internal optimizer, executor bug fixes(Vadim)
    fix problem where inner loop in < or <= has no rows(Vadim)
    prevent re-commuting join index clauses(Vadim)
    fix join clauses for multiple tables(Vadim)
    fix hash, hashjoin for arrays(Vadim)
    fix btree for abstime type(Vadim)
    large object fixes(Raymond)
    fix buffer leak in hash indexes (Vadim)
    fix rtree for use in inner scan (Vadim)
    fix gist for use in inner scan, cleanups (Vadim, Andrea)
    avoid unnecessary local buffers allocation (Vadim, Massimo)
    fix local buffers leak in transaction aborts (Vadim)
    fix file manager memory leaks, cleanups (Vadim, Massimo)
    fix storage manager memory leaks (Vadim)
    fix btree duplicates handling (Vadim)
    fix deleted rows reincarnation caused by vacuum (Vadim)
    fix SELECT varchar()/char() INTO TABLE made zero-length fields(Bruce)
    many psql, pg_dump, and libpq memory leaks fixed using Purify (Igor)

    Enhancements
    ------------
    attribute optimization statistics(Bruce)
    much faster new btree bulk load code(Paul)
    BTREE UNIQUE added to bulk load code(Vadim)
    new lock debug code(Massimo)
    massive changes to libpg++(Leo)
    new GEQO optimizer speeds table multitable optimization(Martin)
    new WARN message for non-unique insert into unique key(Marc)
    update x=-3, no spaces, now valid(Bruce)
    remove case-sensitive identifier handling(Bruce,Thomas,Dan)
    debug backend now pretty-prints tree(Darren)
    new Oracle character functions(Edmund)
    new plaintext password functions(Dan)
    no such class or insufficient privilege changed to distinct messages(Dan)
    new ANSI timestamp function(Dan)
    new ANSI Time and Date types (Thomas)
    move large chunks of data in backend(Martin)
    multicolumn btree indexes(Vadim)
    new SET var TO value command(Martin)
    update transaction status on reads(Dan)
    new locale settings for character types(Oleg)
    new SEQUENCE serial number generator(Vadim)
    GROUP BY function now possible(Vadim)
    re-organize regression test(Thomas,Marc)
    new optimizer operation weights(Vadim)
    new psql \z grant/permit option(Marc)
    new MONEY data type(D'Arcy,Thomas)
    tcp socket communication speed improved(Vadim)
    new VACUUM option for attribute statistics, and for certain columns (Vadim)
    many geometric type improvements(Thomas,Keith)
    additional regression tests(Thomas)
    new datestyle variable(Thomas,Vadim,Martin)
    more comparison operators for sorting types(Thomas)
    new conversion functions(Thomas)
    new more compact btree format(Vadim)
    allow pg_dumpall to preserve database ownership(Bruce)
    new SET GEQO=# and R_PLANS variable(Vadim)
    old (!GEQO) optimizer can use right-sided plans (Vadim)
    typechecking improvement in SQL parser(Bruce)
    new SET, SHOW, RESET commands(Thomas,Vadim)
    new \connect database USER option
    new destroydb -i option (Igor)
    new \dt and \di psql commands (Darren)
    SELECT "\n" now escapes newline (A. Duursma)
    new geometry conversion functions from old format (Thomas)

    Source tree changes
    -------------------
    new configuration script(Marc)
    readline configuration option added(Marc)
    OS-specific configuration options removed(Marc)
    new OS-specific template files(Marc)
    no more need to edit Makefile.global(Marc)
    re-arrange include files(Marc)
    nextstep patches (Gregor Hoffleit)
    removed Windows-specific code(Bruce)
    removed postmaster -e option, now only postgres -e option (Bruce)
    merge duplicate library code in front/backends(Martin)
    now works with eBones, international Kerberos(Jun)
    more shared library support
    c++ include file cleanup(Bruce)
    warn about buggy flex(Bruce)
    DG/UX, Ultrix, IRIX, AIX portability fixes