发明名称 CACHING EXTERNAL DATA SOURCES FOR SQL PROCESSING
摘要 Techniques are provided for caching external data sources for SQL processing. According to an embodiment, a database system receives a query that requires foreign data from an external data source. In response to receiving the query, the database system determines whether the foreign data currently resides in a cache of the database system. In response to determining that the foreign does not currently reside in the cache, the database system retrieves the foreign data from the external data source, maps the foreign data to a column granule of a table, and stores the column granule in the cache. In another embodiment, the database system receives a second query that requires the foreign data. In response to determining that the foreign data is cached with the stored column granule, the database system retrieves the column granule from the cache.
申请公布号 US2016147833(A1) 申请公布日期 2016.05.26
申请号 US201615012742 申请日期 2016.02.01
申请人 Oracle International Corporation 发明人 Chaudhry Atif;Iyer Chandrasekharan
分类号 G06F17/30 主分类号 G06F17/30
代理机构 代理人
主权项 1. A method for optimizing query processing, the method comprising: storing, at a database system, metadata for an external table; wherein the metadata for the external table defines one or more columns for the external table and how data from an external data source maps to the one or more columns of the external table; receiving, at the database system, a query that requires foreign data from the external data source; in response to receiving the query, determining whether the foreign data currently resides in a cache of the database system; in response to determining that the foreign data does not currently reside in the cache: retrieving the foreign data from the external data source;mapping, based on the metadata for the external table, the foreign data to a column granule of the external table; andstoring the column granule in the cache; wherein the method is performed by one or more computing devices.
地址 Redwood Shores CA US