Advantage Database Server

INDEX SCAN

Advantage SQL Engine

INDEX SCAN

Advantage SQL Engine

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INDEX SCAN

Advantage SQL Engine

This is the first topic This is the last topic  

A table is being scanned in indexed order using a scope. This is generally the most efficient method for returning a subset of rows from a table predicating on restrictions on column values in the table. For example, suppose the restriction is "customer_id = 222" and an index exists on the customer_id column in the table, a scope with the top value of 222 and a bottom value of 222 can be applied using the index to quickly limit the set of rows returned. For this operator,

  The StatementText contains the following information about the table and the index:
  Table Name
  Table Alias
  Tag Name

If the query engine determines that a new index is needed to optimize the query the "Tag Name" will be "Temp".

  The Arguments column lists any restrictions that are optimized using the index.
  The Warning column may indicate that no existing index is available to optimize restriction and the Advantage SQL engine must build an index each time the statement is executed.

See Also

How Indexes are Used by ORDER BY Clauses