发明名称 |
DROPPING COLUMNS FROM A TABLE WITH MINIMIZED UNAVAILABILITY |
摘要 |
Dropping of columns from a table with data availability, where the columns in the table are each associated with a column number, includes: executing a statement to drop a given column in the table and deferring an application of the statement until a reorganization of a current data set including the table. When the reorganization of the current data set is performed, the reorganization includes: updating column numbers for columns in each row of the table using a mapping data structure to remove the given column; loading the plurality of data rows with the updated column numbers into a shadow data set; applying to the shadow data set any changes to the table that are concurrent with the reorganization; updating a schema definition of the table with the updated column numbers; and switching the current data set to the shadow data set. |
申请公布号 |
US2015199393(A1) |
申请公布日期 |
2015.07.16 |
申请号 |
US201414154000 |
申请日期 |
2014.01.13 |
申请人 |
International Business Machines Corporation |
发明人 |
FRISKE Craig A.;LIN Charles H.;LIU Regina J.;MUKAI Jerry;SHYAM Kalpana;VIDMAR Cherri;WATTS Julie A.;YOTHERS Jay A.;ZHONG Binghui |
分类号 |
G06F17/30 |
主分类号 |
G06F17/30 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
Armonk NY US |