solidDB Help : Programming : Using SQL for database administration : Managing indexes : Protection against duplicate indexes
  
Protection against duplicate indexes
solidDB protects against duplicate indexes. Occasionally, the recreation of an index (DROP/CREATE) can fail if other indexes were created whereby the original index became a duplicate index.
For example, you could create a table containing five columns, named A, B, C, D, E, and create the following indexes on the table:
B
AB
BCE
ABC
Index B is used for searching or filtering column B. Index BCE starts with column B. Therefore, queries that use an index for locating column B can use index BCE. The same is the case with indexes AB and ABC. Thus, indexes B and AB are duplicate indexes.
Duplicate indexes have the following adverse effects:
The required storage space increases.
The update performance decreases.
Backup time increases.
If you attempt to create duplicate indexes, index creation fails and solidDB generates the following error:
SOLID Table Error 13199: Duplicate index definition
For more information, see Error codes.
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Managing indexes