Re: [HACKERS] [RFC] new digest datatypes, or generic fixed-len hex types?
On Wednesday 29 July 2009 20:16:48 decibel wrote: bytea doesn't cast well to and from text when you're dealing with hex data; you end up using the same amount of space as a varchar. What would probably work well is a hex datatype that internally works like bytea but requires that the input data is hex (I know you can use encode/decode, but that added step is a pain). A similar argument could be made for base64 encoded data. There is a patch in the queue that adds hex input and output to bytea. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] [RFC] new digest datatypes, or generic fixed-len hex types?
On Jul 28, 2009, at 6:15 AM, Peter Eisentraut wrote: On Monday 27 July 2009 14:50:30 Alvaro Herrera wrote: We've developed some code to implement fixed-length datatypes for well known digest function output (MD5, SHA1 and the various SHA2 types). These types have minimal overhead and are quite complete, including btree and hash opclasses. We're wondering about proposing them for inclusion in pgcrypto. I asked Marko Kreen but he is not sure about it; according to him it would be better to have general fixed-length hex types. (I guess it would be possible to implement the digest types as domains over those.) I think equipping bytea with a length restriction would be a very natural, simple, and useful addition. If we ever want to move the bytea type closer to the SQL standard blob type, this will need to happen anyway. The case for separate fixed-length data types seems very dubious, unless you can show very impressive performance numbers. For one thing, they would make the whole type system more complicated, or in the alternative, would have little function and operator support. bytea doesn't cast well to and from text when you're dealing with hex data; you end up using the same amount of space as a varchar. What would probably work well is a hex datatype that internally works like bytea but requires that the input data is hex (I know you can use encode/decode, but that added step is a pain). A similar argument could be made for base64 encoded data. -- Decibel!, aka Jim C. Nasby, Database Architect deci...@decibel.org Give your computer some brain candy! www.distributed.net Team #1828 -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] [RFC] new digest datatypes, or generic fixed-len hex types?
On Monday 27 July 2009 14:50:30 Alvaro Herrera wrote: We've developed some code to implement fixed-length datatypes for well known digest function output (MD5, SHA1 and the various SHA2 types). These types have minimal overhead and are quite complete, including btree and hash opclasses. We're wondering about proposing them for inclusion in pgcrypto. I asked Marko Kreen but he is not sure about it; according to him it would be better to have general fixed-length hex types. (I guess it would be possible to implement the digest types as domains over those.) I think equipping bytea with a length restriction would be a very natural, simple, and useful addition. If we ever want to move the bytea type closer to the SQL standard blob type, this will need to happen anyway. The case for separate fixed-length data types seems very dubious, unless you can show very impressive performance numbers. For one thing, they would make the whole type system more complicated, or in the alternative, would have little function and operator support. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] [RFC] new digest datatypes, or generic fixed-len hex types?
On Tue, Jul 28, 2009 at 7:15 AM, Peter Eisentrautpete...@gmx.net wrote: On Monday 27 July 2009 14:50:30 Alvaro Herrera wrote: We've developed some code to implement fixed-length datatypes for well known digest function output (MD5, SHA1 and the various SHA2 types). These types have minimal overhead and are quite complete, including btree and hash opclasses. I think equipping bytea with a length restriction would be a very natural, simple, and useful addition. If we ever want to move the bytea type closer to the SQL standard blob type, this will need to happen anyway. +1 merlin -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] [RFC] new digest datatypes, or generic fixed-len hex types?
Alvaro Herrera alvhe...@commandprompt.com writes: We've developed some code to implement fixed-length datatypes for well known digest function output (MD5, SHA1 and the various SHA2 types). These types have minimal overhead and are quite complete, including btree and hash opclasses. We're wondering about proposing them for inclusion in pgcrypto. Wasn't this proposed and rejected before? (Or more to the point, why'd you bother? The advantage over bytea seems negligible.) regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] [RFC] new digest datatypes, or generic fixed-len hex types?
On Mon, Jul 27, 2009 at 10:20 AM, Tom Lanet...@sss.pgh.pa.us wrote: Alvaro Herrera alvhe...@commandprompt.com writes: We've developed some code to implement fixed-length datatypes for well known digest function output (MD5, SHA1 and the various SHA2 types). These types have minimal overhead and are quite complete, including btree and hash opclasses. We're wondering about proposing them for inclusion in pgcrypto. Wasn't this proposed and rejected before? (Or more to the point, why'd you bother? The advantage over bytea seems negligible.) well, one nice things about the fixed length types is that you can keep your table from needing a toast table when you have a bytea in it. merlin -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] [RFC] new digest datatypes, or generic fixed-len hex types?
Merlin Moncure mmonc...@gmail.com writes: On Mon, Jul 27, 2009 at 10:20 AM, Tom Lanet...@sss.pgh.pa.us wrote: Wasn't this proposed and rejected before? (Or more to the point, why'd you bother? The advantage over bytea seems negligible.) well, one nice things about the fixed length types is that you can keep your table from needing a toast table when you have a bytea in it. If you don't actually use the toast table, it doesn't cost anything very noticeable ... regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] [RFC] new digest datatypes, or generic fixed-len hex types?
Merlin Moncure wrote: On Mon, Jul 27, 2009 at 10:20 AM, Tom Lanet...@sss.pgh.pa.us wrote: Alvaro Herrera alvhe...@commandprompt.com writes: We've developed some code to implement fixed-length datatypes for well known digest function output (MD5, SHA1 and the various SHA2 types). These types have minimal overhead and are quite complete, including btree and hash opclasses. We're wondering about proposing them for inclusion in pgcrypto. Wasn't this proposed and rejected before? (Or more to the point, why'd you bother? The advantage over bytea seems negligible.) well, one nice things about the fixed length types is that you can keep your table from needing a toast table when you have a bytea in it. Can't you just set storage on the column to MAIN to stop it being stored in a toast table? cheers andrew -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] [RFC] new digest datatypes, or generic fixed-len hex types?
On Mon, Jul 27, 2009 at 12:02 PM, Andrew Dunstanand...@dunslane.net wrote: Merlin Moncure wrote: On Mon, Jul 27, 2009 at 10:20 AM, Tom Lanet...@sss.pgh.pa.us wrote: Alvaro Herrera alvhe...@commandprompt.com writes: We've developed some code to implement fixed-length datatypes for well known digest function output (MD5, SHA1 and the various SHA2 types). These types have minimal overhead and are quite complete, including btree and hash opclasses. We're wondering about proposing them for inclusion in pgcrypto. Wasn't this proposed and rejected before? (Or more to the point, why'd you bother? The advantage over bytea seems negligible.) well, one nice things about the fixed length types is that you can keep your table from needing a toast table when you have a bytea in it. Can't you just set storage on the column to MAIN to stop it being stored in a toast table? of course. hm. would the input/output functions for the fixed length types be faster? what is the advantage of the proposal? merlin -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
