SB-Tree Index Algorithm

This indexing algorithm provides a good mix of features, similar to the features available from other index types. It is good for general use and is durable, transactional and supports range queries. There are four index types that utilize the SB-Tree index algorithm:

• UNIQUE Does not allow duplicate keys, fails when it encounters duplicates.
• NOTUNIQUE Does allow duplicate keys.
• FULLTEXT Indexes to any single word of text.
• DICTIONARY Does not allow duplicate keys, overwrites when it encounters duplicates.

For more information on FULLTEXT_HASH_INDEX, see FullText Index.

The SB-Tree index algorithm is based on the B-Tree index algorithm. It has been adapted with several optimizations, which relate to data insertion and range queries. As is the case with all other tree-based indexes, SB-Tree index algorithm experiences log(N) complexity, but the base to this logarithm is about 500.

NOTE: There is an issue in the replacement of indexes based on B-Tree with those based on COLA Tree to avoid slowdowns introduced by random I/O operations. For more information see Issue #1756.