On Sat, Feb 17, 2001 at 03:45:30PM -0500, Bruce Momjian wrote: > > Right now the WAL preallocation code (XLogFileInit) is not good enough > > because it does lseek to the 16MB position and then writes 1 byte there. > > On an implementation that supports holes in files (which is most Unixen) > > that doesn't cause physical allocation of the intervening space. We'd > > have to actually write zeroes into all 16MB to ensure the space is > > allocated ... but that's just a couple more lines of code. > > Are OS's smart enough to not allocate zero-written blocks? No, but some disks are. Writing zeroes is a bit faster on smart disks. This has no real implications for PG, but it is one of the reasons that writing zeroes doesn't really wipe a disk, for forensic purposes. Nathan Myers [EMAIL PROTECTED]
- [HACKERS] Re: Re: WAL and commit_d... Brent Verner
- Re: [HACKERS] Re: WAL and commit_d... Tom Lane
- Re: [HACKERS] Re: WAL and commit_d... Nathan Myers
- Re: [HACKERS] Re: WAL and commit_d... Tom Lane
- [HACKERS] Re: WAL and commit_delay Adriaan Joubert
- Re: [HACKERS] Re: WAL and commit_d... Tom Lane
- Re: [HACKERS] Re: WAL and commit_d... Larry Rosenman
- Re: [HACKERS] Re: WAL and commit_d... Tom Lane
- Re: [HACKERS] Re: WAL and commit_d... Nathan Myers
- Re: [HACKERS] Re: WAL and commit_d... Jan Wieck
- Re: [HACKERS] WAL and commit_delay Nathan Myers
- Re: [HACKERS] WAL and commit_delay Jerome Vouillon
- Re: [HACKERS] WAL and commit_delay Tom Lane
- Re: [HACKERS] WAL and commit_delay Matthew Kirkwood
- Re: [HACKERS] WAL and commit_delay Matthew Kirkwood
- Re: [HACKERS] WAL and commit_delay Tom Lane
- Re: [HACKERS] WAL and commit_delay Bruce Momjian
- Re: [HACKERS] WAL and commit_delay Dominic J. Eidson