Interface | Description |
---|---|
OLogSegment |
Basic interface for classes which present log segments of WAL.
|
OWALChanges |
Keep partial changes of a page for a transaction and original values of chunks of page which were
changed using this container.
|
OWALPage |
Basic interface for classes which present pages of WAL.
|
OWALRecord | |
OWriteAheadLog |
Class | Description |
---|---|
MetaDataRecord | |
OAbstractPageWALRecord | |
OAbstractWALRecord |
Abstract WAL record.
|
OAbstractWriteAheadLog | |
OAtomicUnitEndRecord | |
OAtomicUnitStartMetadataRecord | |
OAtomicUnitStartRecord | |
OFileCreatedWALRecord | |
OFileDeletedWALRecord | |
OFileTruncatedWALRecord | |
OHighLevelTransactionChangeRecord | |
OLogSequenceNumber |
Immutable number representing the position in WAL file (LSN).
|
OMemoryWriteAheadLog | |
ONonTxOperationPerformedWALRecord | |
OOperationUnitBodyRecord | |
OOperationUnitId | |
OOperationUnitRecord | |
OPaginatedClusterFactory | |
OUpdatePageRecord | |
OWALChangesTree | |
OWALPageChangesPortion | |
OWALPageV1 |
WAL page is organized using following format:
CRC32 code of page content, it is used to check whether data are broken on disk. 4 bytes
Magic number, randomly generated number which is used to check whether page is broken on
disk. 8 bytes
Amount of free space left on page, which can be used to add new records, 4 bytes
WAL records
Each WAL record is stored using following format:
Flag which indicates that record should be merged with record which is stored on next page.
|
OWALPageV2 |
WAL page is organized using following format:
CRC32 code of page content, it is used to check whether data are broken on disk. 4 bytes
Magic number, randomly generated number which is used to check whether page is broken on
disk. 8 bytes
Amount of free space left on page, which can be used to add new records, 4 bytes
Position of LSN of last record which end is stored on this page, 8 bytes
End of the last record stored in page, 4 bytes
WAL records
Each WAL record is stored using following format:
Flag which indicates that record should be merged with record which is stored on next page.
|
OWALRecordsFactory | |
WALRecordTypes |
Exception | Description |
---|---|
OWALPageBrokenException |
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