CLUSTER equivalent
От | Kevin Murphy |
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Тема | CLUSTER equivalent |
Дата | |
Msg-id | 42EF7112.9040300@genome.chop.edu обсуждение исходный текст |
Ответы |
Re: CLUSTER equivalent
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Список | pgsql-general |
Are the two following options equivalent? OPTION A (ordered insert): CREATE TABLE table1 (cluster_col TEXT, col2 INTEGER); CREATE INDEX idx1 ON table1(cluster_col); INSERT INTO table1 (cluster_col, col2) SELECT cluster_col, col2 FROM table1 ORDER BY cluster_col; OPTION B (unordered insert followed by CLUSTER): CREATE TABLE table1 (cluster_col TEXT, col2 INTEGER); CREATE INDEX idx1 ON table1(cluster_col); INSERT INTO table1 (cluster_col, col2) SELECT cluster_col, col2 FROM table1; CLUSTER idx1 ON table1; Thanks, Kevin Murphy P.S. On another topic, did I gather correctly from a recent thread that it would be more efficient to define the above table (if it were really only two columns) as: create table clustered_tagged_genes (integer pmid, text mention); i.e., with the integer field before the text field?
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