com.bigdata.service

Interface ITxState0

All Known Subinterfaces:

ITx, ITxState

All Known Implementing Classes:

AbstractTransactionService.TxState, Tx

public interface ITxState0

Immutable state for a transaction.

Author:

Bryan Thompson

Method Summary

Methods

Modifier and Type	Method and Description
long	getReadsOnCommitTime() The timestamp of the commit point against which this transaction is reading.
long	getStartTimestamp() The start time for the transaction as assigned by a centralized transaction manager service.

Method Detail

getStartTimestamp

long getStartTimestamp()

The start time for the transaction as assigned by a centralized transaction manager service. Transaction start times are unique and also serve as transaction identifiers. Note that this is NOT the time at which a transaction begins executing on a specific journal as the same transaction may start at different moments on different journals and typically will only start on some journals rather than all.

Returns:

The transaction start time.

See Also:

TODO Rename since the sign indicates read-only vs read-write and hence it can not be directly interpreted as a commitTime? (e.g., getTxId()).

getReadsOnCommitTime

long getReadsOnCommitTime()

The timestamp of the commit point against which this transaction is reading.

Note: This is not currently available on a cluster. In that context, we wind up with the same timestamp for #startTime and #readsOnCommitTime which causes cache pollution for things which cache based on #readsOnCommitTime.

See Also:

Refactor native long tx id to thin object, Add cache for access to historical index views on the Journal by name and commitTime.