Re: [PATCHES] patches for 6.2.1p6 - Mailing list pgsql-hackers

>
> Hi hackers,
>
> I have old patches for version 6.2.1p6 which fix some problems and add
> new features. Here is a short description of each patch file:
>
>
> assert.patch
>
>     adds a switch to turn on/off the assert checking if enabled at compile
>     time. You can now compile postgres with assert checking and disable it
>     at runtime in a production environment.
>
> async-unlisten.patch
>
>     declares Async_Unlisten() external so that it can be called by user
>     modules.
>
> exec-limit.patch
>
>     removes the #ifdef NOT_USED around ExecutorLimit(). It is used.
>
> exitpg.patch
>
>     limits recursive calls to exitpg() preventing an infinite loop
>     if an error is found inside exitpg.
>
> libpgtcl-listen.patch
>
>     Just a change from upper to lowercase of an sql command in libpgtcl,
>     totally harmless.
>
> new-locks.patch
>
>     After long studying and many debugging sessions I have finally
>     understood how the low level locks work.
>     I have completely rewritten lock.c cleaning up the code and adding
>     better assert checking. I have also added some fields to the lock
>     and xid tags for better support of user locks. This patch includes
>     also a patch submitted by Bruce Momjian which changes the handling
>     of lock priorities. It can however be disabled if an option is set
>     in pg_options, see tprintf.patch (Bruce patch works by building
>     the queue in reverse priority order, my old patch kept the queue in
>     decreasing order and traversed it from the other side).
>
> pg-flush.patch
>
>     removes an unnecessary flush in libpq reducing network traffic and
>     increasing performance.
>
> relname.patch
>
>     an utility which returns the relname corresponding to a given oid.
>     Useful for debug messages (see vacum.patch).
>
> sequence.patch
>
>     added a setval() function which enables othe owner of a sequence
>     to set its value without need to delete and recreate it.
>
> sinval.patch
>
>     fixes a problem in SI cache which causes table overflow if some
>     backend is idle for a long time while other backends keep adding
>     entries.
>     It uses the new signal handling implemented in tprintf.patch.
>     I have also increacasesed the max number of backends from 32 to 64 and
>     the table size from 1000 to 5000.
>
> spin-lock.patch
>
>     I'm not sure if this is really useful, but it seems stupid to have
>     a backend wasting cpu cycles in a busy loop while the process which
>     should release the lock is waiting for the cpu. So I added a call
>     to process_yield() if the spin lock can't obtained.
>     This has been implemented and tested only on Linux. I don't know if
>     other OS have process_yield(). If someone can check please do it.
>
> tprintf.patch
>
>     adds functions and macros which implement a conditional trace package
>     with the ability to change flags and numeric options of running
>     backends at runtime.
>     Options/flags can be specified in the command line and/or read from
>     the file pg_options in the data directory.
>     Running backends can be forced to update their options from this file
>     by sending them a SIGHUP signal (this is the convention used by most
>     unix daemons so I changed the meaning of SIGHUP).
>     Options can be debugging flags used by the trace package or any other
>     numeric    value used by the backend, for example the deadlock_timeout.
>     Having flags and options specified at runtime and changed while the
>     backends are running can greatly simplify the debugging and tuning
>     of the database. New options can be defined in utils/misc/trace.c and
>     include/utils/trace.h.  As an example of the usage of this package
>     see lock.c and proc.c which make use of new runtime options.
>
>     Old files using int flags or variables can be easily changed to
>     use the new package by substituting the old variable with a #define
>     like in the following example:
>
>       /* int my_flag = 0; */
>       #include "trace.h"
>        #define my_flag pg_options[OPT_MYFLAG]
>
>     I have done it in postgres.c and some other files and now I can turn
>     on/off any single debug flag on the fly with a simple shell script.
>     I have removed the IpcConfigTip() from ipc.c, it should better be
>     described in the postgres manual instead of being printed on stderr.
>
>     This patch provides also a new format of debugging messages which
>     are always in a single line with a timestamp and the backend pid:
>
>       #timestamp          #pid    #message
>       980127.17:52:14.173 [29271] StartTransactionCommand
>       980127.17:52:14.174 [29271] ProcessUtility:  drop table t;
>       980127.17:52:14.186 [29271] SIIncNumEntries: table is 70% full
>       980127.17:52:14.186 [29286] Async_NotifyHandler
>       980127.17:52:14.186 [29286] Waking up sleeping backend process
>       980127.19:52:14.292 [29286] Async_NotifyFrontEnd
>       980127.19:52:14.413 [29286] Async_NotifyFrontEnd done
>       980127.19:52:14.466 [29286] Async_NotifyHandler done
>
>     This improves the readability of the log and allows one to understand
>     exactly which backend is doing what and at which time. It also makes
>     easier to write simple awk or perl scripts which monitor the log to
>     detect database errors or problem, or to compute transaction times.
>
>     The patch changes also the meaning of signals used by postgres, as
>     described by the following table:
>
>             postmaster                backend
>
>     SIGHUP      kill(*,sighup)            read_pg_options
>     SIGINT        kill(*,sigint), die            die
>     SIGCHLD        reaper                -
>     SIGTTIN        ignored                -
>     SIGTTOU        ignored                -
>     SIGQUIT        die                    handle_warn
>     SIGTERM        kill(*,sigterm), kill(*,9), die    die
>     SIGCONT        dumpstatus                -
>     SIGPIPE        ignored                die
>     SIGFPE        -                    FloatExceptionHandler
>     SIGTSTP        -                    ignored (alive test)
>     SIGUSR1        kill(*,sigusr1), die        quickdie
>     SIGUSR2        kill(*,sigusr2)            Async_NotifyHandler
>                             (also SI buffer flush)
>
>     The main changes to the old implementation are SIGQUIT instead of
>     SIGHUP to handle warns, SIGHUP to reread pg_options and redirection
>     to all backends of SIGHUP, SIGINT, SIGTERM, SIGUSR1 and SIGUSR2.
>     In this way some of the signals sent to the postmaster can be sent
>     automatically to all the backends. To shut down postgres one needs
>     only to send a SIGTERM to postmaster and it will stop automatically
>     all the backends. This new signal handling mechanism is also used
>     to prevent SI cache table overflows: when a backend detects the SI
>     table full at 70% it simply sends a signal to the postmaster which
>     will wake up all idle backends and make them flush the cache.
>
> vacuum.patch
>
>     adds a debug message to vacuum that prints the name of a table or
>     index *before* vacuuming it, if the verbose keyword is set.
>     This is useful to know which table is causing troubles if a
>     vacuum all crashes. Currently table information is printed only
>     at the end of each vacuum operation and is never printed if the
>     vacuum crashes.
>
> --
> Massimo Dal Zotto

Massimo, now that 6.3 is released, any chance of getting these patches
against the 6.3 source code?

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