database - How to select first record prior/after a given timestamp in KDB? -

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i pulling in records 1min leading timestamp (e.g. if timestamp i'm interested in 2014.04.14t09:30):

select prices timestamp within 2014.04.14t09:29 2014.04.14t09:30, stock=`goog

however, not robust. previous record may @ 09:25am , query returns nothing. query may return hundreds of records if there have been lot of price changes, though need last record returned.

i know can done asof join, want avoid time being prices big @ present.

i interested in doing same, in finding first record after given timestamp.

note prices splayed table

select last record before given timestamp:

q)select price timestamp<2014.04.14t09:30,stock=`goog,i=last

select first record after given timestamp:

q)select price timestamp>2014.04.14t09:30,stock=`goog,i=first

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