Re: [HACKERS] Estimating total amount of shared memory required by postmaster

2011-06-03 Thread Alvaro Herrera
Excerpts from Tom Lane's message of jue jun 02 15:49:53 -0400 2011: > Alexey Klyukin writes: > > - Try to actually allocate the shared memory in a way postmaster does this > > nowadays, if the process fails - analyze the error code to check whether > > the > > failure is due to the shmmax or

Re: [HACKERS] Estimating total amount of shared memory required by postmaster

2011-06-03 Thread Alexey Klyukin
On Jun 2, 2011, at 10:49 PM, Tom Lane wrote: > Alexey Klyukin writes: >> We've recently come across the task of estimating the size of shared memory >> required for PostgreSQL to start. > >> ... > >> - Try to actually allocate the shared memory in a way postmaster does this >> nowadays, if th

Re: [HACKERS] Estimating total amount of shared memory required by postmaster

2011-06-02 Thread Heikki Linnakangas
On 02.06.2011 21:58, Alexey Klyukin wrote: Hello, We've recently come across the task of estimating the size of shared memory required for PostgreSQL to start. This comes from the problem of validating postgresql.conf files (http://archives.postgresql.org/pgsql-hackers/2011-03/msg01831.php), i.e

Re: [HACKERS] Estimating total amount of shared memory required by postmaster

2011-06-02 Thread Alvaro Herrera
Excerpts from Tom Lane's message of jue jun 02 15:49:53 -0400 2011: > The results of such a test wouldn't be worth the electrons they're > written on anyway: you're ignoring the likelihood that two instances of > shared memory would overrun the kernel's SHMALL limit, when a single > instance would

Re: [HACKERS] Estimating total amount of shared memory required by postmaster

2011-06-02 Thread Tom Lane
Alexey Klyukin writes: > We've recently come across the task of estimating the size of shared memory > required for PostgreSQL to start. > ... > - Try to actually allocate the shared memory in a way postmaster does this > nowadays, if the process fails - analyze the error code to check whether

[HACKERS] Estimating total amount of shared memory required by postmaster

2011-06-02 Thread Alexey Klyukin
Hello, We've recently come across the task of estimating the size of shared memory required for PostgreSQL to start. This comes from the problem of validating postgresql.conf files (http://archives.postgresql.org/pgsql-hackers/2011-03/msg01831.php), i.e. checking that the server will be able to st