增加了三种新的 Postgres 内部数据类型 （datetime，timespan，和 circle）．固定了Points，boxes, paths, 和 polygons 的输出格式．在 misc.out 中的 polygon （多边形）的输出只是相对原先的回归测试输出进行了错误检查．
Postgres v6.1 提供了一个可选的使用 基因 算法的优化器．这些算法在对包含多个侯选项或多个表（优化器需要对表达式值进行排序选择时）的查询输出进行排序时表现得更为随机．有好几个回归测试项目显式地修改了结果的排序，这样就对优化器选择不敏感了．有几个对数据类型的回归测试先天的时乱序的（如 点和时间间隔），与这些类型相关的测试显式的置于 set geqo to 'off' 和 reset geqo 范畴内．
对数组声明（包围在量化值周围的大括号）的解释看起来在最早的回归测试的过程中的某时被改变了．现在的 ./expected/*.out 文件反映了这个新的解释，但却有可能是错误的．
float8 的回归测试至少在某些平台上会失败．这是因为对 pow() 和 exp() 的不同的实现方法以及用于溢出和溢入（underflow）条件的信号机制的不同造成的．
在随机测试中的"随机"结果回导致"随机"测试"失败"，因为回归测试是简单的用 diff 进行比较的．不过，"随机"测试在我的机器上（Linux/gcc/i686）看起来好象并没有产生随机结果．
Bug Fixes --------- packet length checking in library routines lock manager priority patch check for under/over flow of float8(Bruce) multi-table 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 indices (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 memmory leaks, cleanups (Vadim, Massimo) fix storage manager memmory leaks (Vadim) fix btree duplicates handling (Vadim) fix deleted tuples re-incarnation 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 multi-table 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) multi-column 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 WIN32-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