摘要:
A system and method of logless atomic data movement. An internal transaction is started within a multi-level storage architecture, the internal transaction to merge data from the first level storage structure to the second level storage structure. Committed data is read from a first level storage structure of the multi-level storage architecture as specified by the internal transaction. The committed data from the first level storage structure is inserted into a second level storage structure in a bulk insertion process, and the committed data is marked as being deleted from the first level storage. The internal transaction is then committed to the multi-level storage architecture when the committed data has been inserted into the second level storage structure.
摘要:
A system and method of query processing in a multi-level storage system having a unified table architecture. A query is received by a common query execution engine connected with the unified table architecture, the query specifying a data record. The common query execution engine performs a look-up for the data record based on the query at the first level storage structure. If the data record is not present at the first level storage structure, the common query execution engine performs separate look-ups in each of the second level storage structure and the main store.
摘要:
A multi-level storage architecture and method of performing a partial merge are disclosed. A main store is partitioned into a passive main part and an active main part, the active main part being empty at a start of the partial merge, the passive main part storing encoded data records of the main store that are not subject to the partial merge. A values index corresponding to a sorted dictionary of the passive main part is set to a cardinality of n. The data records of a second level storage structure is merged into the active main part, the active main part having a dictionary that starts with a value of n+1, such that the merging into the active main part continues an encoding scheme according to the values index of the passive main part.
摘要:
The subject matter described herein relates to implementation of a dictionary in a column-based, in-memory database where values are not stored directly, rather, for each column, a dictionary is created with all distinct values. For each row, a reference to the corresponding value in the dictionary is stored. In one aspect, data is stored in a memory structure organized in a column store format defined by a plurality of columns and a plurality of rows. A dictionary for each column in the memory structure is generated. The dictionary has distinct values for each column. A reference to the dictionary is generated for each column in the memory structure. The dictionary and the reference to the dictionary are stored in the memory structure.
摘要:
The multi-level storage system and method of deleting first level storage structure pages or records without record locks. The method includes determining whether a record to be deleted from the first level storage structure has any uncommitted write operation, and if the record has an uncommitted write operation, the record is kept in the first level storage structure. Record-moved version information is added to the record to designate the record being moved from the first level storage structure to the second level storage structure. Data change operations are executed for the record based on the record-moved version information without waiting until the record's movement from the first level storage structure to the second level storage structure finishes.
摘要:
Techniques and solutions are provided for performing transactions within a database system that stores database data using a row store and a column store. For example, a transaction that performs operations to update data in both the row store and the column store can use the same transaction object. The state of the transaction can be atomically changed. For example, the state of the transaction object can be atomically changed from uncommitted to committed (e.g., set to a commit identifier to represent the committed state).
摘要:
A multi-level storage architecture and method of performing a partial merge are disclosed. A main store is partitioned into a passive main part and an active main part, the active main part being empty at a start of the partial merge, the passive main part storing encoded data records of the main store that are not subject to the partial merge. A values index corresponding to a sorted dictionary of the passive main part is set to a cardinality of n. The data records of a second level storage structure is merged into the active main part, the active main part having a dictionary that starts with a value of n+1, such that the merging into the active main part continues an encoding scheme according to the values index of the passive main part.
摘要:
Techniques and solutions are provided for performing transactions within a database system that stores database data using a row store and a column store. For example, a transaction that performs operations to update data in both the row store and the column store can use the same transaction object. The state of the transaction can be atomically changed. For example, the state of the transaction object can be atomically changed from uncommitted to committed (e.g., set to a commit identifier to represent the committed state).
摘要:
The multi-level storage system and method of deleting first level storage structure pages or records without record locks. The method includes determining whether a record to be deleted from the first level storage structure has any uncommitted write operation, and if the record has an uncommitted write operation, the record is kept in the first level storage structure. Record-moved version information is added to the record to designate the record being moved from the first level storage structure to the second level storage structure. Data change operations are executed for the record based on the record-moved version information without waiting until the record's movement from the first level storage structure to the second level storage structure finishes.
摘要:
A system and method of logless atomic data movement. An internal transaction is started within a multi-level storage architecture, the internal transaction to merge data from the first level storage structure to the second level storage structure. Committed data is read from a first level storage structure of the multi-level storage architecture as specified by the internal transaction. The committed data from the first level storage structure is inserted into a second level storage structure in a bulk insertion process, and the committed data is marked as being deleted from the first level storage. The internal transaction is then committed to the multi-level storage architecture when the committed data has been inserted into the second level storage structure.