I'm working on a system that uses merged tables with insert method LAST,
and occasionally the application runs a LOAD DATA INFILE with a pretty big
input data set. During the load data, other users running selects are
As it stands at this time, some of the constituent merged tables in the
merge set have deleted rows (i.e., "holes").
I read in the documentation
concurrent selects are permitted during a LOAD DATA INFILE if the free
space is first defragmented, but it doesn't specifically address the
situation of merged tables.
Provided I have run OPTIMIZE TABLES, should I expect a multi-user
application to successfully perform concurrent selects while the lengthy
load data statement is running?
And furthermore, assuming one or more of the constituent tables has free
space (i.e., "holes"), do I need to run OPTIMIZE TABLES on each
constituent file of the merge set separately, or do I run it on the
defined merge table?