[HACKERS] determining a type oid from the name
Say I'm writing an extension X, and I want to process data values from another extension that creates type Y (e.g. an hstore), what's the best way to determine the Oid of type Y in my module X code? SPI code that runs select 'something'::Y and then examines the oid in SPI_tuptable? Or do we have a utility function I have missed that, given a type name and the current search path will give me back the type Oid? 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] determining a type oid from the name
On 22 February 2012 18:00, Andrew Dunstan and...@dunslane.net wrote:
Say I'm writing an extension X, and I want to process data values from
another extension that creates type Y (e.g. an hstore), what's the best way
to determine the Oid of type Y in my module X code? SPI code that runs
select 'something'::Y and then examines the oid in SPI_tuptable? Or do we
have a utility function I have missed that, given a type name and the
current search path will give me back the type Oid?
Does this help?
test=# SELECT pg_typeof('4834.34'::numeric)::oid;
pg_typeof
---
1700
(1 row)
--
Thom
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Re: [HACKERS] determining a type oid from the name
Thom Brown t...@linux.com wrote:
Does this help?
test=# SELECT pg_typeof('4834.34'::numeric)::oid;
pg_typeof
---
1700
(1 row)
Wouldn't it be easier to do this instead?
test=# SELECT 'numeric'::regtype::oid;
oid
--
1700
(1 row)
-Kevin
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Re: [HACKERS] determining a type oid from the name
On 22 February 2012 18:34, Kevin Grittner kevin.gritt...@wicourts.gov wrote:
Thom Brown t...@linux.com wrote:
Does this help?
test=# SELECT pg_typeof('4834.34'::numeric)::oid;
pg_typeof
---
1700
(1 row)
Wouldn't it be easier to do this instead?
test=# SELECT 'numeric'::regtype::oid;
oid
--
1700
(1 row)
Well I may have misread the problem. I thought it was that for a
particular data value, the oid of the type of that value was needed.
--
Thom
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Re: [HACKERS] determining a type oid from the name
On 02/22/2012 01:36 PM, Thom Brown wrote:
On 22 February 2012 18:34, Kevin Grittnerkevin.gritt...@wicourts.gov wrote:
Thom Brownt...@linux.com wrote:
Does this help?
test=# SELECT pg_typeof('4834.34'::numeric)::oid;
pg_typeof
---
1700
(1 row)
Wouldn't it be easier to do this instead?
test=# SELECT 'numeric'::regtype::oid;
oid
--
1700
(1 row)
Well I may have misread the problem. I thought it was that for a
particular data value, the oid of the type of that value was needed.
Maybe I need to be more clear. The C code I'm writing will process
composites. I want to cache the Oids of certain non-builtin types in the
function info's fn_extra, and then be able to test whether or not the
fields in the composites are of those types.
cheers
andrew
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Re: [HACKERS] determining a type oid from the name
Andrew Dunstan and...@dunslane.net writes: Maybe I need to be more clear. The C code I'm writing will process composites. I want to cache the Oids of certain non-builtin types in the function info's fn_extra, and then be able to test whether or not the fields in the composites are of those types. What's your basis for identifying those types in the first place? Name? Doesn't seem terribly robust if the other extension can be installed in some random schema. But anyway, something in parser/parse_type.c ought to help you with that --- maybe parseTypeString? 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] determining a type oid from the name
On 02/22/2012 03:20 PM, Tom Lane wrote: Andrew Dunstanand...@dunslane.net writes: Maybe I need to be more clear. The C code I'm writing will process composites. I want to cache the Oids of certain non-builtin types in the function info's fn_extra, and then be able to test whether or not the fields in the composites are of those types. What's your basis for identifying those types in the first place? Name? Doesn't seem terribly robust if the other extension can be installed in some random schema. But anyway, something in parser/parse_type.c ought to help you with that --- maybe parseTypeString? Thanks, that might do the trick. I fully agree it's not bulletproof, but I'm not sure what alternative there is. 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] determining a type oid from the name
Andrew Dunstan and...@dunslane.net writes: I fully agree it's not bulletproof, but I'm not sure what alternative there is. If you know the type has been installed as an extension you can look at the extension's content in pg_depend, much like \dx+ does, limiting to only types whose name matches. Regards, -- Dimitri Fontaine http://2ndQuadrant.fr PostgreSQL : Expertise, Formation et Support -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
