ASSM by increasing the randomness of the distribution of data to reduce contention. In the ASSM, the complicated process of choosing different basic blocks are inserted rows. Therefore, we used to date as the insertion sequence or order of the table ...
One problem: there is no value on the query plan may affect the implementation of ORACLE. Problems reproduced as follows: SQL> conn ysp / ysp Connected. SQL> DROP TABLE TEST PURGE; Table dropped. SQL> CREATE TABLE TEST (ID CHAR (8), COLNO VA ...
When calculating the Cardinality, ORACLE will first use the DENSITY. If you manually modify the NUM_DISTINCT DENSITY then change will follow. However, in turn, if modified DENSITY, NUM_DISTINCT will not change. SQL> SELECT * FROM V $ VERSION; BANN ...
PL / SQL table --- table () function usage / * PL / SQL table --- table () function usage: Use table () function, we can PL / SQL to return a result set instead of table. oracle memory table in the query and report more often used, its speed relative ...
How to copy the link line? Bank link good imitation, as follows: create table test (x int primary key, a char (2000), b char (2000), c char (2000), d char (2000), e char (2000) ) Tablespace test2; test2 block size is 8K, 5 δΈͺ char (2000) in the field, ...
Today, a problem encountered in the experiment, that is, delete the SYS user will be listed under the error: ORA-12988: can not remove the tables are listed SYS. Himself tried to test it other DDL operations SYS user can: SQL> show user USER is &q ...
join table summary statement select count (*) from test, test1 where test.id = test1.id-- the intersection of select count (*) from test inner join test1 on test.id = test1.id-- the intersection of select count (*) from test cross join test1 - Cartes ...
(The following only in the "=" was the case of the entry into force, LIKE not work.) Sometimes we do not want to check the time and other functions through the lower or upper case and put out the contents of all queries, such as from sqlser ...
1, create a test table, test, and insert 10000 rows of data; SQL> create table test (id int); SQL> begin 2 for i in 1 .. 10000 loop 3 insert into test values (i) 4 end loop; 5 end; 6 / SQL> commit; 2, create a stored procedure SHOW_SPACE: Fi ...
Oracle provides a DBMS_REPAIR package used to discover, identify and modify the data files in the bad blocks. Any tools are not a panacea, the use of this package will also bring about loss of data, table and index return data inconsistency, integrit ...
Experimental environment: zhsy_test table has 200,000 rows. id very good selectivity, the field is unique. a3 field selectivity is not good, only three kinds of value. rn rn SQL statement: select * from zhsy_test where id <1000 and a3 = 'thin& ...
Creating a Test Table create table CLOB_TEST (ID number (10), CLOB_TEXT CLOB)
rn rn rn About Virtual Index (Virtual Index) Study: NinGoo (http://ningoo.itpub.net) Published on: 2007.05.16 11:25 Category: Oracle Source: http://ningoo.itpub.net/post/2149/288057 -------------------------------------------------- ------------- rn ...
1. CLOB field insertion clob types of data directly insert characters long and may be due to an error, so use the object form of insertion. Example: First, create a table with CLOB field: create table test (id INTEGER, content clob); Then insert a nu ...
SQL> desc test Name Null? Type ----------------------------------------- -------- -- ---------------- ID NUMBER - Table test duplicate records 1,10 SQL> select * from test; ID ---------- 1 2 3 4 10 1 1 1 1 1 10 11 rows selected. - Query the tab ...
