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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: <>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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optimize ungroup columns operation in kdb

I am trying to flatten some columns of a table into a single column. My current approach is to enlist those columns into a single column and then use ungroup on table to flatten it. But this approach is very inefficient, takes more than 2 seconds on ...

Sam1 by New Contributor
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