Partition Stream-to-Relation Operators Windows

1-12 Oracle Complex Event Processing CQL Language Reference TxnId, ValidLoopCashForeignTxn.ACCT_INTRL_ID, TRXN_BASE_AM, ADDR_CNTRY_CD, TRXN_LOC_ADDR_SEQ_ID from viewq3[NOW], ValidLoopCashForeignTxn where viewq3.ACCT_INTRL_ID = ValidLoopCashForeignTxn.ACCT_INTRL_ID ]]query rules processor Oracle CQL supports the following relation-to-stream operators: ■ IStream: insert stream. IStreamR contains all r,T where r is in R at time T but r is not in R at time T-1. For more information, see IStream Relation-to-Stream Operator on page 4-24. ■ DSteam: delete stream. DStreamR contains all r,T where r is in R at time T-1 but r is not in R at time T. For more information, see DStream Relation-to-Stream Operator on page 4-25. ■ RStream: relation stream. RStreamR contains all r,T where r is in R at time T. For more information, see RStream Relation-to-Stream Operator on page 4-26. By default, Oracle CEP includes an operation indicator in the relations it generates so you can identify insertions, deletions, and, when using UPDATE SEMANTICS, updates. For more information, see Section 1.1.1.3, Relations and Oracle CEP Tuple Kind Indicator .

1.1.4.1 Default Relation-to-Stream Operator

Whenever an Oracle CQL query produces a relation that is monotonic, Oracle CQL adds an IStream operator by default. A relation R is monotonic if and only if Rt1 is a subset of Rt2 whenever t1 = t2. Oracle CQL use a conservative static monotonicity test. For example, a base relation is monotonic if it is known to be append-only: S[Range Unbounded] is monotonic for any stream S; and the join of two monotonic relations is also monotonic. If a relation is not monotonic for example, it has a window like S[range 10 seconds], it is impossible to determine what the query author intends IStream, DStream, or RStream, so Oracle CQL does not add a relation-to-stream operator by default in this case.

1.1.5 Stream-to-Stream Operators

Typically, you perform stream to stream operations using the following: ■ A stream-to-relation operator to turn the stream into a relation. For more information, see Section 1.1.3, Stream-to-Relation Operators Windows .