Обсуждение: CRC function?
Looked at contrib and didn't see it. Anyone knows if there is a CRC fuction available for PostgreSQL. As an example of how I would use it. Imagine a table with 3 columns id,text, crc_val I could then do something like: select id from <table> where crc(text) <> crc_val;
Francisco Reyes wrote: > Looked at contrib and didn't see it. > Anyone knows if there is a CRC fuction available for PostgreSQL. > > As an example of how I would use it. > Imagine a table with 3 columns > id,text, crc_val > > I could then do something like: > select id from <table> where crc(text) <> crc_val; Sure see contrib/pgcrypto/README: Hashes: MD5, SHA1, CRC32, CRC32B, GOST, TIGER, RIPEMD160, ^^^^^^^^^^^^^ -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 853-3000 + If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill, Pennsylvania 19026
On Mon, 8 Jul 2002, Bruce Momjian wrote: > Francisco Reyes wrote: > > Looked at contrib and didn't see it. > > Anyone knows if there is a CRC fuction available for PostgreSQL. > > > > As an example of how I would use it. > > Imagine a table with 3 columns > > id,text, crc_val > > > > I could then do something like: > > select id from <table> where crc(text) <> crc_val; > > Sure see contrib/pgcrypto/README: > > Hashes: MD5, SHA1, CRC32, CRC32B, GOST, TIGER, RIPEMD160, CRC32 is not installed/supported. Wrote to the author asking him how difficult it would be to add.
Francisco Reyes wrote: > On Mon, 8 Jul 2002, Bruce Momjian wrote: > > > Francisco Reyes wrote: > > > Looked at contrib and didn't see it. > > > Anyone knows if there is a CRC fuction available for PostgreSQL. > > > > > > As an example of how I would use it. > > > Imagine a table with 3 columns > > > id,text, crc_val > > > > > > I could then do something like: > > > select id from <table> where crc(text) <> crc_val; > > > > Sure see contrib/pgcrypto/README: > > > > Hashes: MD5, SHA1, CRC32, CRC32B, GOST, TIGER, RIPEMD160, > > CRC32 is not installed/supported. > Wrote to the author asking him how difficult it would be to add. Oh, yea, I see that now. Strange. We use CRC in the backend WAL code. Funny it isn't already coded somewhere. -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 853-3000 + If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill, Pennsylvania 19026
On Mon, 8 Jul 2002, Bruce Momjian wrote: > Francisco Reyes wrote: > > On Mon, 8 Jul 2002, Bruce Momjian wrote: > > > > CRC32 is not installed/supported. > > Wrote to the author asking him how difficult it would be to add. > > Oh, yea, I see that now. Strange. We use CRC in the backend WAL code. > Funny it isn't already coded somewhere. How difficult you think it would be to have a user visible function for it then?
Francisco Reyes wrote: > On Mon, 8 Jul 2002, Bruce Momjian wrote: > > > Francisco Reyes wrote: > > > On Mon, 8 Jul 2002, Bruce Momjian wrote: > > > > > > CRC32 is not installed/supported. > > > Wrote to the author asking him how difficult it would be to add. > > > > Oh, yea, I see that now. Strange. We use CRC in the backend WAL code. > > Funny it isn't already coded somewhere. > > How difficult you think it would be to have a user visible function for it > then? Very easy. I thought others had already done it already. Seems it should be available. -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 853-3000 + If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill, Pennsylvania 19026
On Mon, 8 Jul 2002, Bruce Momjian wrote: > Francisco Reyes wrote: > > On Mon, 8 Jul 2002, Bruce Momjian wrote: > > > > How difficult you think it would be to have a user visible function for it > > then? > > Very easy. I thought others had already done it already. Seems it > should be available. How do we go about from here? I have a project where it would help me tons if I could get this.