Re: proposal: searching in array function - array_position

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От Pavel Stehule
Тема Re: proposal: searching in array function - array_position
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Msg-id CAFj8pRAXwxo_=HxSSww-DaADfThWb1NKkr4bnpVv-HHwJw7agw@mail.gmail.com
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Ответ на Re: proposal: searching in array function - array_position  (Jim Nasby <Jim.Nasby@BlueTreble.com>)
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2015-01-16 17:57 GMT+01:00 Jim Nasby <Jim.Nasby@bluetreble.com>:
On 1/16/15 3:39 AM, Pavel Stehule wrote:
I am proposing a simple function, that returns a position of element in array.

Yes please!

FUNCTION array_position(anyarray, anyelement) RETURNS int

That won't work on a multi-dimensional array. Ideally it needs to accept a slice or an element and return the specifier for the slice.

theoretically you can use this function for md arrays too. This function returns offset, and you can calculate a Nd possition

so maybe better name -- array_offset or some similar

Regards

Pavel
 

This wouldn't be so bad if we had an easier way to extract subsets of an array, but even that is really ugly because whatever you extract keeps the original number of dimensions.

Implementation is simple (plpgsql code)

This would actually be written in C though, yes? Otherwise it's not really any better than just doing an extension...
--
Jim Nasby, Data Architect, Blue Treble Consulting
Data in Trouble? Get it in Treble! http://BlueTreble.com

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