I want to create a snapshot of customer table and also add reference date when the snapshot was taken.
select * from customer_dump;
select * from customer_snapshot;
select count(*) into b
from user_tables
where table_name = upper('customer_snapshot_dump');
if b = 1 then
execute immediate 'drop table customer_snapshot_dump purge';
end if;
EXECUTE IMMEDIATE 'create table customer_snapshot_dump as (select sysdate as SNAPSHOT_DATE,* from customer_snapshot)';
EXECUTE IMMEDIATE 'drop table customer_snapshot purge';
EXECUTE IMMEDIATE
'create table customer_snapshot as (SELECT * FROM customer_dump
UNION
SELECT * FROM customer_snapshot_dump)';
end;
But the snapshot_date will only make it union all the data. How can the snapshot_date be ignored in the union but still added to the table?
Related
Since complex query takes long time to execute so I want to create a table to keep for future use, I don't want to execute it again. so my idea is that I want to create a table by insert query result into it.
The below is my sample code. It is not working it is just my idea. Thanks
DECLARE
with tab_emp as (
select * from employees
),
tab_dept as
(select * from departments)
procedure create_tab_from_query IS
begin
EXECUTE IMMEDIATE ('create table mytest as select * from '|| tab_emp || ' where 1=0');
end create_tab_from_query;
BEGIN
create_tab_from_query;
dbms_output.put_line(abc);
END;
/
This works:
SQL> with t2 as (select * from t) select * from t2;
L A
--------- ------------------------------------------------------
RUS Русский
But you cannot use WITH in a CREATE TABLE statement as you would like to use.
This cannot work:
SQL> with t2 as (select * from t) create table t3 as select * from t2;
with t2 as (select * from t) create table t3 as select * from t2
*
ERROR at line 1:
ORA-00928: missing SELECT keyword
You should try something simpler without WITH clause:
SQL> create table t3 as select * from t;
Table created.
In your case your PL/SQL code could be simplified this way:
SQL> --
SQL> BEGIN
2 EXECUTE IMMEDIATE ('
3 create table mytest as select * from employees where 1=0');
4 dbms_output.put_line('abc');
5 END;
6 /
abc
PL/SQL procedure successfully completed.
I am working with a huge database with several columns and records. I want to browse a specific table and make a list of the columns that are empty for every record.
Is this possible without refering to all the specific column names?
Thanks for help!
It's possible but if you have a lot data it will last a long time.
create table xxx as select * from dba_objects where rownum < 10000;
prepare test table get table stats. It can be long lasting process.
begin
dbms_stats.gather_table_stats(user,'XXX',estimate_percent =>100);
-- ..
-- others tables to analizye
end;
Generate reports.
select table_name,column_name from user_tab_cols where coalesce(low_value,high_value) is null and table_name in('XXX');
You can use the below script to find out the null columns in your database -
DECLARE
COUNT_COL INT;
SQL_STR VARCHAR2(100);
BEGIN
FOR I IN (SELECT OBJECT_NAME, COLUMN_NAME
FROM USER_OBJECTS UO
JOIN USER_TAB_COLS UTC ON UO.OBJECT_NAME = UTC.TABLE_NAME) LOOP
SQL_STR := 'SELECT COUNT(1) FROM ' || I.OBJECT_NAME || ' WHERE ' || i.COLUMN_NAME || ' IS NOT NULL';
EXECUTE IMMEDIATE SQL_STR INTO COUNT_COL;
IF COUNT_COL = 0 THEN
DBMS_OUTPUT.PUT_LINE(I.COLUMN_NAME);
END IF;
END LOOP;
END;
Here is the fiddle.
Try for all record in table:
SELECT a.owner, a.table_name, b.column_name
FROM all_tables a, all_tab_columns b
WHERE a.table_name = '<TABLE_NAME>'
AND a.table_name = b.table_name
AND a.num_rows = b.num_nulls
For all table
SELECT a.owner, a.table_name, b.column_name
FROM all_tables a, all_tab_columns b
WHERE a.table_name = b.table_name
AND a.num_rows = b.num_nulls
One of my stored procedure recently took around 6 hours which usually takes about 3 hours to complete.
On checking, I found that the cursor is taking the time to execute.
Both the tables are present in my local DB instance.
I need to know what could be the possible reason for this and how the procedure can be fine tuned.
My stored procedure:
create or replace PROCEDURE VMS_DETAILS_D_1 IS
LOG_D1 VARCHAR2(20);
BEGIN
/* IDENTIFY PARTITION */
SELECT partition_name into LOG_D1 FROM all_tab_partitions a WHERE table_name = 'LOG' AND TABLE_OWNER='OWNER1' and partition_position IN
(SELECT MAX (partition_position-1) FROM all_tab_partitions b WHERE table_name = a.table_name AND a.table_owner = b.table_owner);
execute immediate 'DROP TABLE TAB1 PURGE';
COMMIT;
EXECUTE IMMEDIATE 'create table TAB1 Nologging as
select /*+ Parallel(20) */ TRANSACTIONID,TIME_STAMP from OWNER1.log partition('||LOG_D1||')
where ( MESSAGE = ''WalletUpdate| Request for Estel Update is Processed'' or MESSAGE = ''Voucher Core request processed'')';
EXECUTE IMMEDIATE 'CREATE INDEX IDX_TAB1 on TAB1(TRANSACTIONID)';
DBMS_STATS.GATHER_TABLE_STATS (ownname => 'OWNER2' , tabname => 'TAB1',cascade => true, estimate_percent => 10,method_opt=>'for all indexed columns size 1', granularity => 'ALL', degree => 1);
DECLARE
CURSOR resp_cur
IS
select TRANSACTIONID,to_char(max(TIME_STAMP),'DD-MM-YYYY HH24:MI:SS') TIME_STAMP from TAB1
where TRANSACTIONID in (select ORDERREFNUM from TAB2
where ORDERREFNUM like 'BV%') group by TRANSACTIONID;
BEGIN
FOR l IN resp_cur
LOOP
update TAB2
set TCTIME=l.TIME_STAMP
where ORDERREFNUM=l.TRANSACTIONID;
COMMIT;
END LOOP;
END;
end;
First off, DDL has an implicit commit, so you don't need a commit after your drop table.
Secondly, why are you dropping the table and recreating it instead of just truncating the table and inserting into it?
Thirdly, why loop around a cursor to do an update, when you can do it in a single update statement?
If you absolutely must store the data in a separate table, I would rewrite your procedure like so:
CREATE OR REPLACE PROCEDURE vms_details_d_1 IS
log_d1 VARCHAR2(20);
BEGIN
/* IDENTIFY PARTITION */
SELECT partition_name
INTO log_d1
FROM all_tab_partitions a
WHERE table_name = 'LOG'
AND table_owner = 'OWNER1'
AND partition_position IN (SELECT MAX(partition_position - 1)
FROM all_tab_partitions b
WHERE table_name = a.table_name
AND a.table_owner = b.table_owner);
EXECUTE IMMEDIATE 'TRUNCATE TABLE TAB1 reuse storage';
EXECUTE IMMEDIATE 'insert into TAB1 (transactionid, time_stamp)'||CHR(10)||
'select /*+ Parallel(20) */ TRANSACTIONID,TIME_STAMP from OWNER1.log partition(' || log_d1 || ')'||CHR(10)||
'where MESSAGE in (''WalletUpdate| Request for Estel Update is Processed'', ''Voucher Core request processed'')';
EXECUTE IMMEDIATE 'CREATE INDEX IDX_TAB1 on TAB1(TRANSACTIONID)';
dbms_stats.gather_table_stats(ownname => 'OWNER2',
tabname => 'TAB1',
cascade => TRUE,
estimate_percent => 10,
method_opt => 'for all indexed columns size 1',
granularity => 'ALL',
degree => 1);
MERGE INTO tab2 tgt
USING (SELECT transactionid,
max(time_stamp) ts
FROM tab1
GROUP BY transactionid) src
ON (tgt.transactionid = src.transactionid)
WHEN MATCHED THEN
UPDATE SET tgt.tctime = to_char(src.ts, 'dd-mm-yyyy hh24:mi:ss'); -- is tab2.tctime really a string? If it's a date, remove the to_char
COMMIT;
END vms_details_d_1;
/
If you're only copying the data to make it easier to do the update, you don't need to - instead, you can do it all in a single DML statement, like so:
CREATE OR REPLACE PROCEDURE vms_details_d_1 IS
log_d1 VARCHAR2(20);
BEGIN
/* IDENTIFY PARTITION */
SELECT partition_name
INTO log_d1
FROM all_tab_partitions a
WHERE table_name = 'LOG'
AND table_owner = 'OWNER1'
AND partition_position IN (SELECT MAX(partition_position - 1)
FROM all_tab_partitions b
WHERE table_name = a.table_name
AND a.table_owner = b.table_owner);
EXECUTE IMMEDIATE 'MERGE INTO tab2 tgt'||CHR(10)||
' USING (SELECT transactionid,'||CHR(10)||
' MAX(time_stamp) ts'||CHR(10)||
' FROM owner1.log partition(' || log_d1 || ')'||CHR(10)||
' GROUP BY transactionid) src'||CHR(10)||
' ON (tgt.transactionid = src.transactionid)'||CHR(10)||
'WHEN MATCHED THEN'||CHR(10)||
' UPDATE SET tgt.tctime = to_char(src.ts, ''dd-mm-yyyy hh24:mi:ss'')'; -- is tab2.tctime really a string? If it's a date, remove the to_char
COMMIT;
END vms_details_d_1;
/
If you know the predicate(s) which define the partition you're after, you can use those in your query, thus removing the need to find the partition name and therefore needing dynamic SQL.
Okay you procedure needs lots of enhancment:
In the below query you can use user_tab_partitions instead of all_tab_partitions.
SELECT partition_name
into LOG_D1
FROM all_tab_partitions a
WHERE table_name = 'LOG'
AND TABLE_OWNER = 'OWNER1'
and partition_position IN
(SELECT MAX(partition_position - 1)
FROM all_tab_partitions b
WHERE table_name = a.table_name
AND a.table_owner = b.table_owner);
You have to include a checking on the table tab1 incase if it doesnt exists and no need to commit here, its not a DML statement.
execute immediate 'DROP TABLE TAB1 PURGE';
COMMIT;
No need to update the statistics in the procedure, especially its a newly table created and the index is already created, and its only one index.
The above might slightly improve the performance but you have to check that there is an index on table log for column message ( but as i said its wrong modeling) also check query plan on tab2 if it needs a index.
This is the wrong approach, what you're doing is update TAB2 the number of times the records in cursor resp_cur, I would switch to a merge.
Is there a way to count how many rows inserted into table by
Create table tbl1 as select * from tbl2;
statement which performed from PL\SQL function (execute immediate)?
When I'm using SQL%ROWCOUNT the result is 1.
Thanks.
You can try this. As mentioned in my comment you need to do it as followed. Remember that you need again to use Execute immediate else you get an issue that tab1 is undefined.
DECLARE
vsql VARCHAR2 (200);
cnt NUMBER;
BEGIN
vsql := 'create table tbl1 as select * from employee';
EXECUTE IMMEDIATE vsql;
vsql := 'select count(1) from tbl1';
EXECUTE IMMEDIATE vsql INTO cnt;
DBMS_OUTPUT.put_line (cnt);
END;
You can do one thing. You can first create an empty table tbl1 from tbl2. Then insert data using SELECT and then use- SQL%ROWCOUNT.
CREATE TABLE tbl1 AS SELECT * FROM tbl2 WHERE 1=2;
INSERT INTO tbl1 SELECT * FROM tbl2;
DBMS_OUTPUT.PUT_LINE ('No. of rows inserted in TBL2 from TBL1 = ' || SQL%ROWCOUNT);
The question is very common, but I am facing one single issue in there for which I am not able to find the answer.
What I have to do is, create a table if the table does not exist.
But while creating the table, I need to create it from the select query(which is result of JOIN of two tables).
This is for "ORACLE SQL DEVELOPER" / "PL/SQL".
The query I am using is:
DECLARE
count_matching_tbl BINARY_INTEGER := 0;
BEGIN
SELECT COUNT(*)
INTO count_matching_tbl
FROM dba_tables
WHERE LOWER(table_name) = 'testtable';
IF(count_matching_tbl = 0)
THEN
EXECUTE IMMEDIATE ( ' CREATE TABLE testtable AS (SELECT A.*, B.* from tab1 A JOIN tab2 B ON A.id = B.RID WHERE 1=2)');
END IF;
END;
If tab1 and tab2 table has same name column then ambiguity occure while creating table and inserting record so instead of * replace table column which is add in testtable like
CREATE TABLE testtable AS (SELECT A.cola1, B.colb1 from tab1 A JOIN tab2 B ON A.id = B.RID WHERE 1=2
ask your dba to give "select on dba_tables " to your schema .
Since you are using a pl/sql procedure , you need to have permissions granted directly to you rather than through a role.
The issue was because of the static SQL data.
The table was created dynamically, but the rest of the statements were trying to access the static data.
To solve this, I have created two anonymous blocks, the first one having the create table statement, commit it and end the block.
The next anonymous block will have the rest of the statements to be executed after the IF clause.
This solved my problem.
DECLARE
count_matching_tbl BINARY_INTEGER := 0;
BEGIN
SELECT COUNT(*)
INTO count_matching_tbl
FROM dba_tables
WHERE LOWER(table_name) = 'testtable';
IF(count_matching_tbl = 0)
THEN
EXECUTE IMMEDIATE ( ' CREATE TABLE testtable AS (SELECT A.*, B.* from tab1 A JOIN tab2 B ON A.id = B.RID WHERE 1=2)');
COMMIT;
END IF;
END;
/
BEGIN
-- Rest of the database execution statements
COMMIT;
END;
/