removeindex

Removeindex is a general term used in computing to describe the operation of deleting an element from a sequence at a given position, or, in database contexts, the act of removing an index from a table's schema. In programming languages that use mutable arrays or lists, removing an item by index typically shifts subsequent elements to fill the gap and changes the length of the collection. The operation is often named removeIndex, remove_at, erase, or similar, depending on language. Most implementations perform error checking for invalid indices; negative indices or indices greater than or equal to the length usually raise an exception or return a sentinel value. Time complexity is commonly O(n) for array-backed structures due to shifting.

In databases, removing an index means dropping the index object from the schema to stop maintaining it; this can improve write performance but may slow queries that relied on the index. The exact syntax varies by DBMS (for example, DROP INDEX index_name on some systems, or DROP INDEX ... ON table_name on others).

In immutable data structures, remove by index returns a new collection with the element removed, leaving the original unmodified. In practice, the choice of approach depends on performance requirements and the data structure in use.

See also: splice, pop, erase, drop index, index management.