摘要:
A method of invalidating an unused log file in a database includes examining a discard log information storage area and determining if a discard log exists. If the discard log exists, the log is invalidated. The headers of each of the log files that have been fully invalidated are then invalidated. The discard log is then fully invalidated and a new log file may be generated on top of the discarded log. The method may be interrupted by a failure, a changeover, or crash and will be repeated until it completes.
摘要:
A linked data structure verification system to verify the integrity of at least one linked data structure simultaneously by way of a verification setup phase and an integrity verification phase. Individual nodes are retrieved from a memory device and examined seriatim in optimal memory device location order. Nodes are retrieved and examined in optimal memory device location order for maximum memory device retrieval performance. Expected and/or actual node information about nodes in a given linked data structure are temporarily stored as records in an integrity verification table for only as much time as is necessary to verify any part of the node information prior to excising one or more unnecessary records from the integrity verification table.
摘要:
An on-line dynamic shrink facility sets an allocation fence in a file and moves data from above the fence to below the fence. The fence is based on a target size for the file. When all the data above the fence is moved below the fence, the space above the fence is freed. The target size can be a specified size, an original size for the file when it was created, or a size calculated by examining the amount of space used and adding in an amount of desired free space. Resources that are required to move the data, such as old and new allocation units for the data, or that will be impacted by movement of the data, such as index entries, are locked or latched to prevent corruption of the data while it is being moved. The operations are performed in discreet transactions which are immediately committed to minimize the impact on other users of the file.