To drop multiple columns at once, you use the following statement: ALTERTABLEtable_nameDROP( column1, column2, column3 );Code language:SQL (Structured Query Language)(sql) For example, the following statement drops theemailandphonecolumns from thesupplierstable: ALTERTABLEsuppliersDROP( email, pho...
SMON 会每 15 分钟将 shared pool 中的 predicate columns 的数据刷新到 col_usage$基表中(until periodically about every 15 minutes SMON flush the data into the data dictionary),另外当 instance shutdown 时 SMON 会扫描 col_usage$并找出已被 drop 表的相关 predicate columns 记录,并删除这部 分”orph...
Virtual columns 虚拟列- Oracle 11g virtual table columns are columns that are actually functions ("create table t1 (c1 number, c2 number, c3 as (c1+c2) virtual"), and similarly, virtual indexes that are based on functions. Also seeOracle 11g function-based virtual columns. S...
5、IMP-00093: Inconsistency between dumpfile constraint definition for table PNR_INSPECT_PLAN_ITEM with columns ("ID") 原因:起因是在导入的过程中要导入系统生成的约束,类似SYS_C0027639, metalink上只提到了这个原因,但是以前很多次的imp应该都是有这样系统生成的约束名,并没有报错过,所以应该还是有另外的...
In a relational database, all data is stored in two-dimensional tables that are composed of rows and columns. Oracle Database enables you to store data, update it, and efficiently retrieve it, with a high degree of performance, reliability, and scalability. Oracle Database is composed of ...
The PL/SQL block in Example 6-10 queries multiple values into PL/SQL tables, with and without bulk binds. Without bulk bind, PL/SQL sends a SQL statement to the SQL engine for each selected employee, leading to context switches that slow performance. ...
This error message means that a double value in the source database is outside the allowable range for the Oracle Server. In this case, the Migration Workbench migrates all other columns in the row as normal and migrates a null value for the column that contains the double value. The err...
new capability to create multiple indexes on the same column list. It’s even a feature listed in the New Features GuideThis can be particularly useful when you want to change the index definition in some way but you want to reduce the time in which the corresponding columns might not ...
Control SQL Server export behavior DROP_ROWVERSION PostgreSQL has no equivalent to rowversion datatype and feature, if you want to remove these useless columns, enable this directive. Columns of datatype 'rowversion' or 'timestamp' will not be exported. CASE_INSENSITIVE_SEARCH Emulate the same ...
To know the columns, or rather the attributes shown here, use the describe command to display the attributes of the cell disk.CellCLI> describe celldisk name modifiable comment modifiable creationTime deviceName devicePartition diskType errorCount freeSpace freeSpaceMap id interleaving lun physicalDisk ...