kdb+ and q
Q+A on all things kdb+ database and the q language
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Get first row from a group

Hi, if I like to select the last row from a group, I can just doselect by xxx from tableif there similar syntax to select the first row? Other than using "first" for all elements?

carfield1 by New Contributor
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Publishing data from R

Hello, I am fairly new to R and I would like to publish data into a qserver, wondering if anyone has experience doing this?I haven't really found any examples anywhere.I have opened a connection but am not really sure how to publish the correct Q typ...

how to append a new column to hdb file?

hi, I have stored some hdb files, but, now, I have to modify the table schema, so the hdb data need to be modified too. Is there a function for me to add a new column to the hdb files directly?

Isaac by New Contributor
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RE: [personal kdb+] unique index

X-Originating-IP: Workspace Webmail 5.16.0Message-Id: <20160101200302.85f80dae80d1d2f2e266ec6278e6cbe8.4a08ca37d3.wbe@email07.europe.secureserver.net>From: "David Demner \(AquaQ\)" To: personal-kdbplus@googlegroups.comSubject...

unique index

Why is unique index not improving performance in this case? Furthermore, applying group attribute on cust column in table a surprising makes this 10x slower. Why? n:1300000a:([]cust:n?`8; v1:n?100; v2:n?100; v3:n?100)/ with unique indexb1:`u#exec dis...

Sam1 by New Contributor
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