3、method_opt: FOR ALL [INDEXED | HIDDEN] COLUMNS[size_clause] FOR COLUMNS [size clause] column[size_clause] [,column [size_clause]...] 字段数据分布不均衡时,建立柱状图(直方图): 柱状图统计信息:索引字段列值建立统计信息 多列统计信息:复合索引列建立统计信息 表达式统计信息:对函数索引键建立统计信...
比如优化器决定Oracle是以什么样的方式方式访问数据,是全表扫描(Full Table Scan) 、索引范围扫描(Index Range Scan)还是全索引快速扫描(INDEX Fast Full Scan, INDEX_FFS). 对于多表关联查询,它负责确定表之间以一种什么样的方式来关联,比如Hash Join 还是 NESTED LOOPS或者是MERGE JOIN。 这些因素直接决定着SQL...
You cannot define a foreign key constraint in a CREATE TABLE statement that contains an AS subquery clause. Instead, you must create the table without the constraint and then add it later with an ALTER TABLE statement. 你不能在CREATE TABLE语句中包含AS子查询子句定义一个外键约束。相反,你必须创建...
USE_CONCATThe USE_CONCAT hint forces combined OR conditions in the WHERE clause of a query to be transformed into a compound query using the UNION ALL set operator. Normally, this transformation occurs only if the cost of the query using the concatenations is cheaper than the cost without the...
Here’s a script that I used to build the test data, with scope for a few variations in testing. You’ll notice that the “create table” includes an “order by” clause that is close to the sorting requirement of the over() clause that appears in the query. The results I’ve show...
i_index_clause dr$索引名$X索引作成用のパラメータ句。内部CREATE INDEX文の終わりに追加するstorage句およびtablespace句を指定します。デフォルト句は、'COMPRESS 2'で、この索引表を圧縮するようにOracle Textに指示します。 この圧縮によってディスク領域が節約され、問合せパフォーマンスが向上...
In previous releases, certain SQL queries that contained a WITH clause could return the wrong result. This is fixed. (BugDB #32989462 - Backport of BugDB #32928200) In previous releases, when using the TimesTen Kubernetes Operator, if the active and standby databases failed simultaneously after ...
nested tables, 13-12 object tables, 13-8, 13-12 locks, 24-30 parallelism, 23-32 index-organized tables, 23-31 partition attributes, 11-26 storage parameters, 4-18 triggers, 19-7 CREATE TABLESPACE statement TEMPORARY clause, 3-13 CREATE TEMPORARY TABLE statement, 10-11 CR...
Sets the disignated parameter to a String and executes a non-padded comparison with a SQL CHAR. CHAR data in the database is padded to the column width. This leads to a limitation in using the setCHAR() method to bind character data into the WHERE clause of a SELECT statement--the ...
fix issue related to using returning clause with prepared statement will hang add lob fetch=inline which is equal to lob fetch=pre complete fix for data raceversion 2.8.8introduce new connection break using go-routines thanks to @rheilek return BLOB as longRAW and CLOB,NCLOB as LONG in lob...