{"id":440,"date":"2010-02-08T13:27:10","date_gmt":"2010-02-08T10:27:10","guid":{"rendered":"http:\/\/blog.yavor.info\/?p=440"},"modified":"2010-02-09T13:13:19","modified_gmt":"2010-02-09T10:13:19","slug":"%d0%bf%d1%80%d0%b0%d0%b2%d0%b8%d0%bb%d0%b5%d0%bd-%d0%b8%d0%bd%d0%b4%d0%b5%d0%ba%d1%81-%d0%b3%d1%80%d0%b5%d1%88%d0%b5%d0%bd-%d0%bf%d0%be%d0%b4%d1%85%d0%be%d0%b4","status":"publish","type":"post","link":"http:\/\/blog.yavor.info\/?p=440","title":{"rendered":"\u041f\u0440\u0430\u0432\u0438\u043b\u0435\u043d \u0438\u043d\u0434\u0435\u043a\u0441, \u0433\u0440\u0435\u0448\u0435\u043d \u043f\u043e\u0434\u0445\u043e\u0434"},"content":{"rendered":"<p>\u0422\u043e\u0432\u0430 \u0449\u0435 \u0432\u043b\u0435\u0437\u0435 \u0432 \u043a\u0430\u0442\u0435\u0433\u043e\u0440\u0438\u044f quick checks. \u041f\u0440\u0435\u0434\u0432\u0430\u0440\u0438\u0442\u0435\u043b\u043d\u043e \u043a\u0430\u0437\u0432\u0430\u043c, \u0447\u0435 (\u0432\u0441\u0435 \u043e\u0449\u0435) \u043d\u0435 \u043f\u043e\u0437\u043d\u0430\u0432\u0430\u043c \u0434\u043e\u0431\u0440\u0435 \u0441\u0438\u0441\u0442\u0435\u043c\u0430\u0442\u0430, \u0437\u0430 \u043a\u043e\u044f\u0442\u043e \u0441\u0442\u0430\u0432\u0430 \u0434\u0443\u043c\u0430.<\/p>\n<p>\u0414\u043d\u0435\u0441 \u043c\u0438 \u0438\u0437\u043b\u0435\u0437\u0435 \u0438\u043d\u0442\u0435\u0440\u0435\u0441\u0435\u043d \u0432\u044a\u043f\u0440\u043e\u0441: \u0435\u0434\u043d\u0430 \u0442\u0430\u0431\u043b\u0438\u0446\u0430 \u0438\u043c\u0430 \u043d\u044f\u043a\u043e\u043b\u043a\u043e \u0434\u0435\u0441\u0435\u0442\u043a\u0438 \u043c\u0438\u043b\u0438\u043e\u043d\u0430 \u0440\u0435\u0434\u0430, \u0441 \u0434\u0430\u043d\u043d\u0438 \u043e\u0442 8 \u0433\u043e\u0434\u0438\u043d\u0438 \u043d\u0430\u0441\u0430\u043c. \u0418\u043c\u0430 (not null) \u043a\u043e\u043b\u043e\u043d\u043a\u0430 \u0441 \u0434\u0430\u0442\u0430, \u043f\u043e \u043a\u043e\u044f\u0442\u043e \u0438\u043c\u0430 \u0438\u043d\u0434\u0435\u043a\u0441. \u041a\u043e\u043b\u043e\u043d\u043a\u0430\u0442\u0430 \u043d\u044f\u043c\u0430 \u0445\u0438\u0441\u0442\u043e\u0433\u0440\u0430\u043c\u0430. \u041a\u043e\u0433\u0430\u0442\u043e \u043f\u0443\u0441\u043d\u0435\u043c \u0437\u0430\u044f\u0432\u043a\u0430\u0442\u0430 <code>select count(1) from tab where date_col > sysdate-1<\/code>, \u0441\u044a\u0432\u0441\u0435\u043c \u043f\u0440\u0430\u0432\u0438\u043b\u043d\u043e, \u0441\u0435 \u0438\u0437\u043f\u043e\u0437\u043b\u0432\u0430 \u0441\u044a\u043e\u0442\u0432\u0435\u0442\u043d\u0438\u044f\u0442 \u0438\u043d\u0434\u0435\u043a\u0441, \u0442.\u0435. \u043d\u0435 \u0441\u043c\u0435 \u0432 \u0442\u0430\u0437\u0438 \u0441\u043a\u0443\u0447\u043d\u0430 \u0441\u0438\u0442\u0443\u0430\u0446\u0438\u044f <em>&#8222;Oracle \u043d\u0435 \u043c\u0438 \u0438\u0437\u043f\u043e\u043b\u0437\u0432\u0430 \u0438\u043d\u0434\u0435\u043a\u0441\u0430&#8220;<\/em>. \u041e\u0431\u0430\u0447\u0435 \u0441\u0435 \u043f\u0440\u0430\u0432\u0438 Index Fast Full Scan (wtf???), \u043a\u043e\u0435\u0442\u043e \u0435\u0441\u0442\u0435\u0441\u0442\u0432\u0435\u043d\u043e, \u0434\u0430\u0432\u0430 \u043d\u0435\u0437\u0430\u0434\u043e\u0432\u043e\u043b\u0438\u0442\u0435\u043b\u043d\u0430 \u043f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0438\u0442\u0435\u043b\u043d\u043e\u0441\u0442:<\/p>\n<pre lang=\"plsql\">\r\nSQL> set autot traceonly explain\r\nSQL> select count(1) from tab where date_col>SYSDATE-1;\r\n\r\nExecution Plan\r\n----------------------------------------------------------\r\nPlan hash value: 2096840410\r\n\r\n----------------------------------------------------------------------------------------\r\n| Id  | Operation             | Name           | Rows  | Bytes | Cost (%CPU)| Time     |\r\n----------------------------------------------------------------------------------------\r\n|   0 | SELECT STATEMENT      |                |     1 |     8 | 10461   (7)| 00:02:06 |\r\n|   1 |  SORT AGGREGATE       |                |     1 |     8 |            |          |\r\n|*  2 |   INDEX FAST FULL SCAN| I_TAB_DATE_COL |  5038K|    38M| 10461   (7)| 00:02:06 |\r\n----------------------------------------------------------------------------------------\r\n\r\nPredicate Information (identified by operation id):\r\n---------------------------------------------------\r\n\r\n   2 - filter(\"DATE_COL\">SYSDATE@!-1)\r\n<\/pre>\n<p>\u0421\u043f\u043e\u0440\u0435\u0434 explain plan, \u0438\u0437\u043f\u043e\u043b\u0437\u0432\u0430\u043d\u0435\u0442\u043e \u043d\u0430 IFFS \u0432\u043e\u0434\u0438 \u0434\u043e cost \u043e\u0442 ~10000, \u0434\u043e\u043a\u0430\u0442\u043e \u043f\u0440\u0438 hint <code>INDEX_SS_ASC<\/code> cost-\u0430 \u0435 15000. <\/p>\n<pre lang=\"plsql\">\r\nSQL> SELECT \/*+INDEX_SS_ASC(t I_TAB_DATE_COL)*\/ COUNT(1) FROM tab t WHERE date_col>SYSDATE-1;\r\n\r\nExecution Plan\r\n----------------------------------------------------------\r\nPlan hash value: 547665643\r\n\r\n------------------------------------------------------------------------------------\r\n| Id  | Operation         | Name           | Rows  | Bytes | Cost (%CPU)| Time     |\r\n------------------------------------------------------------------------------------\r\n|   0 | SELECT STATEMENT  |                |     1 |     8 | 15875   (1)| 00:03:11 |\r\n|   1 |  SORT AGGREGATE   |                |     1 |     8 |            |          |\r\n|*  2 |   INDEX RANGE SCAN| I_TAB_DATE_COL |  5038K|    38M| 15875   (1)| 00:03:11 |\r\n------------------------------------------------------------------------------------\r\n\r\nPredicate Information (identified by operation id):\r\n---------------------------------------------------\r\n\r\n   2 - access(\"DATE_COL\">SYSDATE@!-1)\r\n<\/pre>\n<p>\u041f\u0440\u0438 \u0430\u043d\u043e\u043c\u0430\u043b\u0438\u0438 \u0432 cost, \u043e\u0441\u043e\u0431\u0435\u043d\u043e \u0432 \u0435\u043b\u0435\u043c\u0435\u043d\u0442\u0430\u0440\u043d\u0438 \u0437\u0430\u044f\u0432\u043a\u0438, \u0432\u0435\u0434\u043d\u0430\u0433\u0430 \u0433\u043b\u0435\u0434\u0430\u043c \u0441\u0442\u0430\u0442\u0438\u0441\u0442\u0438\u043a\u0438\u0442\u0435, \u0437\u0430\u0449\u043e\u0442\u043e \u0432 99.9999% \u043e\u0442 \u0441\u043b\u0443\u0447\u0430\u0438\u0442\u0435, \u0442\u0430\u043c \u0441\u0435 \u043a\u0440\u0438\u0435 \u0437\u0430\u0435\u043a\u0430. <\/p>\n<p>\u0421\u0442\u0430\u0442\u0438\u0441\u0442\u0438\u043a\u0438\u0442\u0435 \u0441\u0438 \u0431\u044f\u0445\u0430 \u041e\u041a, \u0441\u044a\u0431\u0440\u0430\u043d\u0438 \u0441\u0430 \u0441\u043a\u043e\u0440\u043e (\u043f\u0440\u0435\u0434\u043d\u0430\u0442\u0430 \u0432\u0435\u0447\u0435\u0440):<\/p>\n<pre lang=\"plsql\">\r\nSQL> set autot off\r\nSQL> select to_char(last_analyzed, 'DD.MM.YYYY HH24:MI:SS')\r\n  from dba_tab_statistics\r\n where owner = 'OWNR'\r\n   and table_name = 'TAB';  \r\n\r\nTO_CHAR(LAST_ANALYZED,'DD.MM.Y\r\n---------------------------------------------------------------------------\r\n07.02.2010 22:03:58\r\n<\/pre>\n<p>\u041f\u0440\u0435\u0434\u0438 \u0434\u0430 \u0437\u0430\u0434\u044a\u043b\u0431\u0430\u044f \u0432 clustering factor \u0438 \u0434\u0440\u0443\u0433\u0438 \u043f\u043e\u0434\u0440\u043e\u0431\u043d\u043e\u0441\u0442\u0438 \u0437\u0430 \u0438\u043d\u0434\u0435\u043a\u0441\u0430, \u043f\u043e\u0433\u043b\u0435\u0434\u043d\u0430\u0445 \u043a\u0430\u043a\u0432\u043e \u0442\u043e\u0447\u043d\u043e \u043f\u0438\u0448\u0435 \u0437\u0430 \u0442\u0430\u0437\u0438 \u043a\u043e\u043b\u043e\u043d\u043a\u0430, \u0442\u0430 \u043e\u043f\u0442\u0438\u043c\u0438\u0437\u0430\u0442\u043e\u0440\u0430 \u0440\u0435\u0448\u0430\u0432\u0430, \u0447\u0435 \u0449\u0435 \u0432\u0437\u0435\u043c\u0435 \u0442\u0432\u044a\u0440\u0434\u0435 \u043c\u043d\u043e\u0433\u043e \u0434\u0430\u043d\u043d\u0438 \u043f\u0440\u0438 range scan.<\/p>\n<pre lang=\"plsql\">\r\nSQL> column low_value format a20\r\nSQL> column high_value format a20\r\nSQL> select low_value, high_value, density\r\n  from dba_tab_col_statistics\r\n where owner = 'OWNR'\r\n   and table_name = 'TAB'\r\n   and column_name = 'DATE_COL';\r\n\r\nLOW_VALUE            HIGH_VALUE              DENSITY\r\n-------------------- -------------------- ----------\r\n78660107173A0A       78710208121319       1.1388E-07\r\n<\/pre>\n<p>\u041e\u043f\u0430&#8230; \u0433\u0440\u0435\u0434\u0430. \u0414\u0430\u043d\u043d\u0438\u0442\u0435 \u0437\u0430 low_value \u0438 high_value \u0441\u0430 \u0432 \u043a\u043e\u043b\u043e\u043d\u043a\u0430 \u0442\u0438\u043f long (\u0445\u0430-\u0445\u0430-\u0445\u0430). \u0421 \u043c\u0430\u043b\u043a\u043e \u0442\u044a\u0440\u0441\u0435\u043d\u0435 \u043d\u0430\u043c\u0435\u0440\u0438\u0445 \u0432 <a href=\"http:\/\/forums.oracle.com\/forums\/thread.jspa?threadID=925388\">OTN<\/a> \u043a\u0430\u043a \u0434\u0430 \u0432\u0438\u0434\u044f \u0434\u0430\u0442\u0430\u0442\u0430 \u0432 \u043f\u043e-\u0440\u0430\u0437\u0431\u0438\u0440\u0430\u0435\u043c \u0444\u043e\u0440\u043c\u0430\u0442<\/p>\n<pre lang=\"plsql\">\r\nSQL> set serveroutput on\r\nDECLARE\r\n  rv RAW(32) := '78710208121319';\r\n  dt DATE := NULL;\r\nBEGIN\r\n  dbms_stats.convert_raw_value(rv, dt);\r\n  dbms_output.put_line(TO_CHAR(dt, 'DD-MM-YYYY hh24:mi:ss'));\r\nEND;\r\n\/\r\n08-02-2013 17:18:24\r\n\r\nPL\/SQL procedure successfully completed.\r\n<\/pre>\n<p>\u0413\u0440\u0435\u0448\u043a\u0430\u0442\u0430 \u0435 \u0432\u044f\u0440\u043d\u0430! \u041e\u043a\u0430\u0437\u0430 \u0441\u0435 \u0447\u0435 \u0438\u043c\u0430 \u043d\u044f\u043a\u043e\u043b\u043a\u043e \u0431\u044a\u0433\u043b\u0438\u0432\u0438 \u0437\u0430\u043f\u0438\u0441\u0430, \u043a\u043e\u0438\u0442\u043e \u0441\u0442\u043e\u044f\u0442 \u0433\u043e\u0434\u0438\u043d\u0438 \u043d\u0430\u043f\u0440\u0435\u0434. \u0421\u044a\u043e\u0442\u0432\u0435\u0442\u043d\u043e \u043f\u0440\u0435\u0434\u0438\u043a\u0430\u0442\u0430 <code>date_col>SYSDATE-1<\/code> \u0432\u0440\u044a\u0449\u0430 3 \u0433\u043e\u0434\u0438\u043d\u0438 \u0434\u0430\u043d\u043d\u0438. \u041f\u0440\u0438 \u043b\u0438\u043f\u0441\u0430\u0442\u0430 \u043d\u0430 \u0445\u0438\u0441\u0442\u043e\u0433\u0440\u0430\u043c\u0438 \u043e\u043f\u0442\u0438\u043c\u0438\u0437\u0430\u0442\u043e\u0440\u0430 \u043d\u044f\u043c\u0430 \u043a\u0430\u043a \u0434\u0430 \u0437\u043d\u0430\u0435, \u0447\u0435 \u0449\u0435 \u0432\u044a\u0440\u043d\u0435 \u043d\u044f\u043a\u043e\u043b\u043a\u043e \u0434\u0435\u0441\u0435\u0442\u043a\u0438\/\u0441\u0442\u043e\u0442\u0438\u0446\u0438 \u0437\u0430\u043f\u0438\u0441\u0438 &#8211; \u0433\u0440\u0443\u0431\u0430\u0442\u0430 \u0441\u043c\u0435\u0442\u043a\u0430 \u043f\u043e\u043a\u0430\u0437\u0432\u0430, \u0447\u0435 \u0449\u0435 \u043f\u0440\u0435\u0440\u043e\u0432\u0438 \u0434\u0430\u043d\u043d\u0438 \u0437\u0430 3 \u0433\u043e\u0434\u0438\u043d\u0438 \u043e\u0442 \u043e\u0431\u0449\u043e \u043d\u0430\u043b\u0438\u0447\u043d\u0438 11 \u043c\u0435\u0436\u0434\u0443 low_value \u0438 high_value.<\/p>\n<p>\u0412 \u0441\u043b\u0443\u0447\u0430\u044f \u0440\u0435\u0448\u0435\u043d\u0438\u0435\u0442\u043e \u0431\u0435\u0448\u0435 \u0434\u0430 \u0441\u0435 \u0437\u0430\u0442\u0440\u0438\u044f\u0442 \u0431\u044a\u0433\u043b\u0438\u0432\u0438\u0442\u0435 \u0434\u0430\u043d\u043d\u0438. \u041d\u043e \u043f\u043e \u043f\u0440\u0438\u043d\u0446\u0438\u043f \u0442\u043e\u0432\u0430 \u0435 \u0438\u0434\u0435\u0430\u043b\u0435\u043d \u043f\u0440\u0438\u043c\u0435\u0440 \u0437\u0430 \u043f\u043e\u043b\u0437\u0430\u0442\u0430 \u043e\u0442 \u0445\u0438\u0441\u0442\u043e\u0433\u0440\u0430\u043c\u0438\u0442\u0435.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u0422\u043e\u0432\u0430 \u0449\u0435 \u0432\u043b\u0435\u0437\u0435 \u0432 \u043a\u0430\u0442\u0435\u0433\u043e\u0440\u0438\u044f quick checks. \u041f\u0440\u0435\u0434\u0432\u0430\u0440\u0438\u0442\u0435\u043b\u043d\u043e \u043a\u0430\u0437\u0432\u0430\u043c, \u0447\u0435 (\u0432\u0441\u0435 \u043e\u0449\u0435) \u043d\u0435 \u043f\u043e\u0437\u043d\u0430\u0432\u0430\u043c \u0434\u043e\u0431\u0440\u0435 \u0441\u0438\u0441\u0442\u0435\u043c\u0430\u0442\u0430, \u0437\u0430 \u043a\u043e\u044f\u0442\u043e \u0441\u0442\u0430\u0432\u0430 \u0434\u0443\u043c\u0430.<\/p>\n<p>\u0414\u043d\u0435\u0441 \u043c\u0438 \u0438\u0437\u043b\u0435\u0437\u0435 \u0438\u043d\u0442\u0435\u0440\u0435\u0441\u0435\u043d \u0432\u044a\u043f\u0440\u043e\u0441: \u0435\u0434\u043d\u0430 \u0442\u0430\u0431\u043b\u0438\u0446\u0430 \u0438\u043c\u0430 \u043d\u044f\u043a\u043e\u043b\u043a\u043e \u0434\u0435\u0441\u0435\u0442\u043a\u0438 \u043c\u0438\u043b\u0438\u043e\u043d\u0430 \u0440\u0435\u0434\u0430, \u0441 \u0434\u0430\u043d\u043d\u0438 \u043e\u0442 8 \u0433\u043e\u0434\u0438\u043d\u0438 \u043d\u0430\u0441\u0430\u043c. \u0418\u043c\u0430 \u043a\u043e\u043b\u043e\u043d\u043a\u0430 \u0441 \u0434\u0430\u0442\u0430, \u043f\u043e \u043a\u043e\u044f\u0442\u043e \u0438\u043c\u0430 \u0438\u043d\u0434\u0435\u043a\u0441. \u041a\u043e\u043b\u043e\u043d\u043a\u0430\u0442\u0430 \u043d\u044f\u043c\u0430 \u0445\u0438\u0441\u0442\u043e\u0433\u0440\u0430\u043c\u0430. \u041a\u043e\u0433\u0430\u0442\u043e \u043f\u0443\u0441\u043d\u0435\u043c \u0437\u0430\u044f\u0432\u043a\u0430\u0442\u0430 <code>select count(1) from tab where date_col > sysdate-1<\/code>, \u0441\u044a\u0432\u0441\u0435\u043c \u043f\u0440\u0430\u0432\u0438\u043b\u043d\u043e, \u0441\u0435 \u0438\u0437\u043f\u043e\u0437\u043b\u0432\u0430 \u0441\u044a\u043e\u0442\u0432\u0435\u0442\u043d\u0438\u044f\u0442 \u0438\u043d\u0434\u0435\u043a\u0441, \u0442.\u0435. \u043d\u0435 \u0441\u043c\u0435 \u0432 \u0442\u0430\u0437\u0438 \u0441\u043a\u0443\u0447\u043d\u0430 \u0441\u0438\u0442\u0443\u0430\u0446\u0438\u044f <em>&#8222;Oracle \u043d\u0435 \u043c\u0438 \u0438\u0437\u043f\u043e\u043b\u0437\u0432\u0430 \u0438\u043d\u0434\u0435\u043a\u0441\u0430&#8220;<\/em>. \u041e\u0431\u0430\u0447\u0435 \u0441\u0435 \u043f\u0440\u0430\u0432\u0438 Index Fast Full Scan (wtf???), \u043a\u043e\u0435\u0442\u043e \u0435\u0441\u0442\u0435\u0441\u0442\u0432\u0435\u043d\u043e, \u0434\u0430\u0432\u0430 \u043d\u0435\u0437\u0430\u0434\u043e\u0432\u043e\u043b\u0438\u0442\u0435\u043b\u043d\u0430 \u043f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0438\u0442\u0435\u043b\u043d\u043e\u0441\u0442:<\/p>\n<p>(<a href=\"http:\/\/blog.yavor.info\/?p=440\">A\u043a\u043e \u0442\u0438 \u0435 \u0438\u043d\u0442\u0435\u0440\u0435\u0441\u043d\u043e, \u0447\u0435\u0442\u0438 \u043d\u0430\u0442\u0430\u0442\u044a\u043a&#8230;<\/a>)<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[],"tags":[],"jetpack_featured_media_url":"","_links":{"self":[{"href":"http:\/\/blog.yavor.info\/index.php?rest_route=\/wp\/v2\/posts\/440"}],"collection":[{"href":"http:\/\/blog.yavor.info\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/blog.yavor.info\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/blog.yavor.info\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/blog.yavor.info\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=440"}],"version-history":[{"count":0,"href":"http:\/\/blog.yavor.info\/index.php?rest_route=\/wp\/v2\/posts\/440\/revisions"}],"wp:attachment":[{"href":"http:\/\/blog.yavor.info\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=440"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/blog.yavor.info\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=440"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/blog.yavor.info\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=440"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}