PL/SQL :: How To Create Special Column Which Represents Result Of A Query
Feb 26, 2013
I have a table MESSAGE which has some billion entries. The columns are msg_id, vehicle_id, timestamp, data, etc.I have another table VEHICLE which holds static vehicle data (about 20k rows) such as vehicle_id, licenceplate, etc.
My first target was to partition the table via timestamp (by range) and subpartition by vehicle_id (by hash).So I could easily drop old data by dropping old partitions and tablespaces.
Now comes the new difficult 2nd target: the messages of some vehicles must be kept forever.My idea is to add a column KEEP_DATA to the table MESSAGE. I could try to partition by timestamp AND KEEP_DATA, subpartion by vehicle_id.The problem of this idea is that i have to update billions of rows.
It would be perfect if there is a possibility to add this KEEP_DATA-flag to the table vehicle.Is there any way to "link" this information to a column in MESSAGE table?
I mean something like this:
alter table MESSAGE
add column (select keep_data from vehicle where VEHICLE.vehicle_id = MESSAGE.vehicle_id as keep_message) ;
Is there some possibility like that? Would the partitioning on this column / statement work?Would the value of the keep_message be calculated on runtime?
If so will the performance influence be noticeable?If so will the performance also sink if the application is querying all rows except the keep_message?
Still today user can enter any special character value in stud_name like L'Pradhan . I want to put a restriction on stud_name so that user can enter only alphabetical value into stud_name column.
I have this table column of varchar2 data type. I need to find out if it contains anything other than numbers or alphabets(basically to see if it contains any special characters in it).
I just need to fetch only those rows that has special characters. How do I get this?
Create small functional indexes for special cases in very large tables.
When there is a column having one values in 99% records and another values that have to be search for, it is possible to create an index using null value. Index will be small and the rebuild fast.
Example
create index vh_tst_decode_ind_if1 on vh_tst_decode_ind (decode(S,'I','I',null),style)
It is possible to do index more selective when the key is updated and there are many records to create more levels in b-tree.
create index vh_tst_decode_ind_if3 on vh_tst_decode_ind (decode(S,'I','I',null), decode(S,'I',style,null) )
To access the record can by like:
SQL> select --+ index(vh_tst_decode_ind_if3) 2 style ,count(*) 3 from vh_tst_decode_ind 4 where 5 decode(S,'I','I',null)='I' 6 group by style 7 ;
PROCEDURE getrecordsForinspection(i_table_name in varchar2, i_thread_id in varchar2, i_max_count in number default null, o_results out sys_refcursor) AS v_sql varchar2(1000):= null;
begin v_sql := 'update '||'i_table_name||' set status = '||'''IN_PROCESS-'||i_thread_id||''''||' Where final_status = '||''''STATUS_ACCEPTED'''||' and ('||i_max_count||' is null or rownum <= '||i_max_count||');';
EXECUTE IMMEDIATE(v_sql); commit; end;
when I execute the above procedure it gives the following error.
ORA-00911: invalid character cause: Identifiers may not start with any ASCII characters other than letters and numbers.$#_ are also allowed after the first character. Identifiers enclosed by double quotes may contain any character other than a double quote. Alternative quotes(q'#....#') can not use spaces, tabs, or carriage returns as delimiters. For all other contexts, consult the SQL language reference Manual.
I think dynamic sql is not executed because of the pipe character in the sql statement.
BANNER Oracle Database 10g Enterprise Edition Release 10.2.0.5.0 - 64bi PL/SQL Release 10.2.0.5.0 - Production "CORE10.2.0.5.0Production" TNS for Linux: Version 10.2.0.5.0 - Production NLSRTL Version 10.2.0.5.0 - Production [code]....
Requirements for the result set:
1. List the root division as column headers 2. Start date is March 15, 2012 3. End date is June 30, 2012 4. Do not skip or omit dates 5. The values under each column are percentages where completed = 'Y' 5a. Example, D5_Total = 277, D5_Completed(Y) = 254, D5_Percent(Y) = 254/277 = 92% 5b. Rounded to whole percentage like 92% and NOT 91.696%
The result set will be used to create a line graph. The graph will show which root division is closer to reaching 100% before the deadline of June 30, 2012.
I want to run below query to get the result set that I am after. But It takes long time even with the indexes...Here in IM_Mapping table is having 1.7 mio records and T_Extract table about 35000 records. All the other tables having below 1000 records
I have the following data (columns IDx, STARTx and DURATION) and want to create the column RESULT. Example:
create table zTEST ( IDx number, STARTx number, DURATION number, RESULT number ); insert into zTEST (IDx, STARTx, DURATION, RESULT) values ( 1 , null , null , null );
[code]...
The logic behind the table is like this: when there is a Start-ID and a Duration, the field Result shall show the Start-ID for the next records (Duration period). Even if there is a new Start-ID in row 9, it is ignored since threre is already a current signal from row 6 which is still running.
I need to write a query which will get me output: 233445, i.e. all the three rows concatenated. How can it be done? I want to do it through sql only and not to use PL/SQL. Is this possible?
I have a sql query which fetch the data from 4 different tables. I want to write the output of that query into a excel or a CSV file without using TOad and all. Let me know is it possible via creating function or procedure.
I have a strange problem with query with like and %.
When I run this script:
ALTER SESSION SET NLS_SORT = 'BINARY_CI'; ALTER SESSION SET NLS_COMP = 'LINGUISTIC'; -- drop table test1; CREATE TABLE TEST1(K1 NVARCHAR2(80)); INSERT INTO TEST1 VALUES ('gsdk');
When i change datatype in column to varchar2 this code work correct.
The execution plan:
PLAN_TABLE_OUTPUT SQL_ID d3d64aupz4bb5, child number 2 select * from TEST1 where k1 like N'Ł%' Plan hash value: 4122059633 Id Operation Name Rows Bytes Cost (%CPU) Time 0 SELECT STATEMENT 2 (100) * 1 TABLE ACCESS FULL TEST1 1 82 2 (0) 00:00:01
QUOTE (thiyagusham @ Mar 27 2012, 11:40 PM) SQL> select * from samp;
NAME DOJ QUAL EMPID ---------- --------------- ---------- ----- sam 21-mar-2012 mca sony 03-jan-2000 mba 10610 maya 21-mar-2012 m.arch sonna 18-mar-2012 mis
[code]...
i want to display in result column 10610 in second row , because emp sony having id "10610 "should i use sub-query ? without sub-query how can i display ?
I have a strange problem with query with like and %.
When I run this script:
ALTER SESSION SET NLS_SORT = 'BINARY_CI'; ALTER SESSION SET NLS_COMP = 'LINGUISTIC'; -- SELECT * FROM NLS_SESSION_PARAMETERS; -- drop table test1; CREATE TABLE TEST1(K1 NVARCHAR2(80));
[code]....
When i change datatype to varchar2 this code work correct.
The execution plan:
PLAN_TABLE_OUTPUT ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ SQL_ID d3d64aupz4bb5, child number 2 ------------------------------------- select * from TEST1 where k1 like N'Ł%'
[code]....
Note - dynamic sampling used for this statement (level=2)
Depending on the no. of distinct dates in table 1 i have to make those many columns in table 2. I m trying to write a Query in SQL. If its not possible in SQL give me PL/SQL procedure.
