MySQL MyISAM keys that use an auto-increment attribute as the secondary part of a multi-column key, allow the generated value to be tightly associated with the primary part of the key, while the auto-increment in InnoDB is just a running number. This forces you to use an attribute for the auto-increment attribute that can accomodate the maximum table size even though a single grouping may never exceed ten. Depending the order of entry the comparison might be
MyISAM:
dog/1
dog/2
cat/1
cat/2
fish/1
fish/2
fish/3
InnoDB:
dog/4
dog/5
cat/1
cat/3
fish/2
fish/6
fish/7
While it does accomplish a natural grouping, it also forces inefficient usage of storage, since you have to accomodate the largest table size. Is there any way around it?
Facing Future - IZ
MyISAM:
dog/1
dog/2
cat/1
cat/2
fish/1
fish/2
fish/3
InnoDB:
dog/4
dog/5
cat/1
cat/3
fish/2
fish/6
fish/7
While it does accomplish a natural grouping, it also forces inefficient usage of storage, since you have to accomodate the largest table size. Is there any way around it?
Facing Future - IZ