What is Table Scan Percent?
A “table scan” happens when a table is accessed sequentially, without the use of indexes. This type of access may indicate inefficiency in statement execution. Table Scan Percent displays, out of all data read by a statement, how much was read using sequential access as opposed to indexed access. Suppose the following attachment: Attachment #1, Reads 230MB, Table Scan 75% In this case, out of the 230MB read by this attachment, 172.5MB (75%) were read using table scans. It is necessary to identify which of the statements issued by this attachment was responsible for this high degree of Table Scans and try to optimize it.
