PL/SQL :: Difference In Num_rows And Count Function
Dec 7, 2012
SELECT COUNT(*) FROM APP.Big_table; Number of record--222653402
This is a big table to get the it's taking 8 minutes time, so that I tried the following SQL to get the count quickly.
SELECT num_rows FROM all_tables WHERE table_NAME='BIG_TABLE'
and owner='APP'; --Number of records 237213998But I got the different count for the two SQLs. Why there is a difference in the count. Which one is correct.
difference between count(1) and count(*). As i know count(*) will give number of rows irrespective of null and count(1) will not count the null.My Oracle version is 10 g.
SQL> select * from t1;
A B C ---------- -------------------- -------------------- 1 2 3 2 5
SQL> select rownum,a.* from t1 a;
ROWNUM A B C ---------- ---------- -------------------- -------------------- 1 1 2 3 2 2 3 5 4 [code]....
I am trying to get a record count of this table and i get 2 different output , select count(*) shows 68560 and after updating the stats the NUM_ROWS shows 68323, why the difference .
SQL> select count(*) from dcepcd;
COUNT(*) ---------- 68560
SQL> select num_rows from dba_tables where table_name='DCEPCD';
Find the date difference. I need to find that how many days the task is pending, if ACT_NAME field switching from 'SET PENDING%' to 'RESUME PENDING%' by using ACTIONTAKENDATETEXT field in the History table.
Example as needed: NoPendingDays = 23 (8+15)
I have attached Create table and Insert table values sample as SQL file.
I know difference between procedure and function.if we want a return value from procedure, we can have OUT parameter. Similarly with function, in addition to returning a value from function, it can also send an OUT parameter value as a return value. That means, in one or the other way we are able to get a return value from both program units. Normally, I would fill a OUT variable with error message when an exception occurs. I use this varaible,after procedure call, to detect if an exception occurred or not. Similar task can be performed by a function, it returns a true/false and a value thru OUT variables.
both program units return values in the form of OUT parameters. Where exactly should we use a function, where exactly should we use a procedure?
difference between Procedure and Function.We Know that Procedure is Basically Used to perform Actions and Functions are Basically Used for Calculations but what would be the exact difference since Actions/Calculations can be done in both Procedure and Functions.Which factors decide whether we need to write a Procedure and in which cases we need Function.
There is a table with column holding 3 NULL values one each in every record. When a count function is applied to the column with a filter on NULLs,it returns 0 instead of 3.
But when count(*)is applied,expected result is returned. Would be interested in knowing about this strange behavior of NULL/Count.
I am trying to get a row count(*) for all the tables in my schema. The NUM_ROWS column in DBA_TABLES is not appropriate in this case because they are as good as the last analyze. So I need to get real time counts.
I tried the following code but I can't seem to catch my error.
DECLARE
l_sql varchar2(150); cursor tablelist is select table_name from dba_tables where owner = 'ME';
Want to understand difference between Concat function and "||" operator. I am getting the same result for both. Below is the test case for your reference.
Select 'H '||' S' From Dual; --Output H S
Select Concat('H ',' S') A From Dual; --Output H S
Select Length('H '||' S') A From Dual; --Output 6
Select Length(Concat('H ',' S')) A From Dual; --Output 6
However, when I compare the num_rows in user_indexes to the num_rows in user_tables, for some indexes I am getting zero rows but over 100k rows in the table.I can see from the last_analyzed col on user_indexes that stats were gathered within seconds of the stats being collected on the tables.
create or replace function getDate(p_joing_date Date,p_sysdate) Return Date; IS v_compltd_mnths; BEGIN SELECT into v_compltd_mnths MONTHS_BETWEEN(TO_DATE('sysdate','MM-DD-YYYY'), TO_DATE('joing_date','MM-DD-YYYY') ) "Months"FROM DUAL; return v_compltd_mnths; END;
I have the following query with analytic function but wrong results on the last column COUNT.
1)I am getting the output order by b.sequence_no column . This is a must. 2)COUNT Column :
I don't want the total count based on thor column hence there is no point in grouping by that column. The actual requirement to achieve COUNT is:
2a -If in the next row, if either the THOR and LOC combination changes to a new value, then COUNT=1 (In other words, if it is different from the following row)
2b-If the values of THOR and LOC repeats in the following row, then the count should be the total of all those same value rows until the rows become different. (In this case 2b-WHERE THE ROWS ARE SAME- also I only want to show these same rows only once. This is shown in the "MY REQUIRED OUTPUT) .
My present query: select r.name REGION , p.name PT, do.name DELOFF, ro.name ROUTE,
[code]...
My incorrect output[PART OF DATA]:Quote: REGIONPT DELOFF ROUTE THOR LOC SEQ COUNT NAASNAAS MAYNOOTHMAYNOOTHR010 DUBLINRD CEL 1 1 NAASNAAS MAYNOOTHMAYNOOTHR010 NEWTOWNRD CEL 2 1
[code]...
My required output[PART OF DATA]-:Quote: REGIONPT DELOFF ROUTE THOR LOC COUNT NAASNAAS MAYNOOTHMAYNOOTHR010 DUBLINRD CEL 1 NAASNAAS MAYNOOTHMAYNOOTHR010 NEWTOWNRD CEL 1 NAASNAAS MAYNOOTHMAYNOOTHR010 PRIMHILL CEL 1
[code]...
NOTE :Count as 1 is correctly coming.But where there is same rows and I want to take the total count on them, I am not getting.
SELECT rp.id r_paper_id, COUNT(*) created, COUNT( CASE WHEN a.approved_yn = 'Y'
[code]....
But it fails, saying that 'single-row subquery returns more than one row' when I introduce the 'unique_users' clause. The remaining fields of the output are correct.
I'm using this code, and it performs fine, but I'm wondering if there is a more elegant way to do it--maybe with "ROLLBACK". Basically (as you can see) I need to get a normal count for each group but also for each group take a percentage of the total count (so all groups pct adds up to 100 (oh yeah, don't test for zero below, but just a test... )
select c.Event, c.code, count(1) as calls, total.total_count, count(1) / total.total_count * 100 as pct_of_total from table1 c
[Code]....
[Edit MC: add code tags, do it yourself next time]
Reg. Area Age <=19 20 <= Age <= 24 25 <=Age <= 29 Total No. of Voters xxxx 10 15 7 32 yyyy 5 7 3 15
I have work out a script but the age is not in a range
select * FROM (select rgs_id_reg_area, count(decode(fbd_age,19,fbd_age)) Age19, count(decode(fbd_age,20,fbd_age)) Age20 FROM rubyvoterstat where vote ='Y' GROUP by rgs_id_reg_area) order by rgs_id_reg_area