Hi team,
Do you know what's the difference between int_delta encoding and int_delta compression?
I was doing a few tests and noticed that when a column (int) is encoded as AUTO, the compression type is delta_int and when it is encoded as deltaval it's uncompressed and encoded as delta_int.
what is the difference between the two?
For perfomance purposes only , does it make sense to encode a high cardinality sorted integer column as deltaval or is it better to leave as Auto?
Thank you
Chaima
Question
What is the difference between int delta encoding and int delta compression?
+2
DELTAVAL computes the min/max over the block and then encodes everything as a delta off the min. The number of bits used per entry depends on l2(max-min). This allows random access, so it is an "encoding". DeltaIntPack compression builds the difference from one record to the next, so it is a compression, because you have to process all the prior records to get to the next one. This is better for increasing sequences than deltaval.
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