Hello all,
I need to copy a large block of rows (start=1,000,000 and stop=5,000,000) from
table a to table b in the same file. Looking at the pytables documentation I
came up with a few options.
Option 1:
for row in a.iterrows(start, stop):
b.append([row[:]])
However a loop in python over millions of rows doesn't seem optimal.
Option 2:
b.append(a.read(start, stop))
All dthe ata is first copied from a to memory before being written to b, which
is not scalable.
Option 3:
Use whereAppend()
This seems the best (assuming the copying of rows from table to table is done
much more efficiently in C than I could do in Python). However whereAppend
doesn't want to run without a condition, and I do not have a condition, just
start and stop parameters....
Did I miss the obvious alternative? Any suggestions?
Best,
Koert
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