Difference between count (*) & count (1)

Jin
I want to know the difference between count and count (*) (1).
Which is effective and why.

Hello

There is no difference between COUNT (*) and the NUMBER (1). They return the same results and are just as effective.

Tags: Database

Similar Questions

What is the difference between Count (*) and Count (1)?

Hello
can you please what is the difference between Count (*) and Count (1)?
I saw that Count (*), Count (1), Count (2)... etc return values from a table. Is there an exact difference between them?

Have you read the forum space FAQ? I'm sure that you don't have because it is answered there.

It is also answered via Google.

The short answer is: there is no difference, unless you use count (1), count (2), etc. instead of count (*) it makes you look like an amateur.

What is the difference between count (1) selection of the tab and select count (*) tab;

What is the difference between count (1) selection of the tab and select count (*) tab;

994122 wrote:

Hello

SQL > set timing on

SQL > select count (*) of the emp

2 where deptno = 30;

COUNT (*)

---------------

6

Elapsed time: 00:00:00.01

SQL > select count (1) of the emp

2 * where deptno = 30

SQL > /.

COUNT (1)

-------------

6

Elapsed time: 00:00:00.01

See that both give the same time

Do you really think the 100th's of a second it takes 6 rows from counting will truly representative of the difference it takes actually?

Such a small data set cannot possibly show no difference to these larger units of time (in the calculation of terms where we have millions of instructions per second in lieu)

As the link to the FAQ provided in the response of Anton (first response on this thread) Watch, count (1) and count (*) are essentially the same, except that count (1) actually get re-written by the query re - write the step of the optimization to make it count (*).

Generally 'count (*)' makes more sense language, because it reads like "count" while "count (1)" reads as "count we ', which does not have as much good sense when you actually count all.

DIFFERENCE BETWEEN count (*) and Count (1)

If this link means
https://jonathanlewis.WordPress.com/2015/01/06/count-4/
It works the same way
Summary: -.
https://www.LinkedIn.com/groups/4251681/4251681-6057436339962474497

Yes, he does. As Jonathan, Oracle rewrites internal count (1) by count (*) in recent versions.

In general, I suggest using count (*), since that's what Oracle prefer of course (it rewrites the other requests to make a count (*) if possible).

Justin

Difference between Satellite R50-B-114 and R50-B-119

I would like to ask if there is a specific difference between these two?
I don't think there is, but I'm curious, because I found two models with exactly the same settings (cpu, ram, hard drive, graphics, sound).
And the price was different, 119 was about $ 100 cheaper.

I found my guy already, however there are still 2 days until I can place my order (weekend). The only difference that I found at toshiba.eu is a hard drive size. My local dealer has them both with SSD of 256 and it was my choice. Does still count as the model even if a hard drive is changed?

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Hello

I have a plan to monitor the 6.1.0.17 WebSphere Application Server (32 bit) and 7.0.0.5 (64-bit)

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Thanks in advance

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Just to add to the excellent answers already posted.

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This Agent will give you JMX information like information of JVM (use of the bunch, son etc.), of the Application and server availability information and other information of JMX/PMI (connections pools, pools of ejb, servlets, jsp, JCA and more).

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Hope this helps

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Hello
I know ckm and flow control. What is the main difference between the Frother and CKM?

CKM is the model of knowledge that ODI will use to check all the constraints you create.

Flow control is the way to a check constraint during the flow of an interface (it's way happens to you in your integration tables [temporary]). This method deletes the data of 'bad' and it will record in a table of $ E. Also, you have some option to recycle errors (next ODI run will try to reuse these data)

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The most used method is the regulator of throughput with certainty, but static electricity has some advantages too.

For example, flow control has only a little when you check duplicate data. When he found it eliminated the two registry (or more if there are more). It's average, you get nothing in the end.

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The summary above capacity data store is interpreted as follows: -.

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Hi all!
In the official document VMware "vsphere-51-configuration-maxima" or "vsphere-55-configuration - maximums.pdf" in the section "ESXi host maximum rates------Maximums calculation" exists in the elements:
"Maximum CPU------logical CPU for each host ' (vSphere 5.1: 160;) vSphere 5.5: 320)
and
"Machine virtual maximums------virtual CPU by host ' (vSphere 5.1: 2048;) vSphere 5.5: 4096)
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And a more complex thing to maximum rates:
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Number of hosts per cluster: 32
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But in the document, we have only 4000 VMs in maximum.
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Thank you

Ramirez,

I understand your question as difference between 1. logic virtual CPU vs / by the hosts and 2. cluster/host Max County VM.

Consider the case below;

2 servers ESXi - 20 mV

ESXi taken 1-4, 2 cores / socket

ESXi 2-8 Sockets, 2 cores / socket

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20 virtual machines - 2 jacks, 2 core / socket

Virtual CPU count - 20 x (2 * 2) = 80

Hope your first confusion is clear now.

And a more complex thing to maximum rates:

Virtual machines per host: 512

Number of hosts per cluster: 32

Therefore, the cluster may be Virtual Machines (maximum): 521 * 32 = 16384

But in the document, we have only 4000 VMs in maximum.

Why?

This means that even if you have 32 Guest and each host can accommodate 512 VMs each the maximum number of virtual machines per cluster may not exceed 4000. And it does not mean that you can have a maximum of VMS (512 * 32).

~ dGeorgey

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New name, same thing.

Adobe will continue to publish updates of Player 11 for a while, but they will not be security update.

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What is the difference between Photoshop CS6 and elements?

vitaltheatre wrote:

Photoshop Elements is NOT the same thing in Photoshop CS6. Photoshop 6 is passed into the creative cloud (CC)

No, there are many versions of Photoshop, older versions don't fade. Photoshop is a program that evolves every evolution Gets a new name and a version number the version number is important when you develop code for Photoshop. If Photoshop 6 is version 6 which evolved to Photoshop 7 version 7 cs version 8 to version 9 of CS2 to CS3 version 10 to version CS4 11 CS 5 version 12-CS6 13 CC version 14-15 version CC2014 version. All this exists. Version 15 is not backward compatible with any previous version of Photoshop functionality and support have been deleted and new features and added support.

CS6 however is a little weird for are different versions of the CS6 is the perpetual version and versions of the subscription and there, not the same thing not everyone has the same characteristics. If you want to split hairs there are actually 5 cs6 version and if you want to count 32-bit and 64-bit modules there are 8. There are only 3 version numbers but for CS6 wit all updates applied. Mac version perpetual 13.0.6 perpetual version 13.0.1.3 Windows and Mac and PC version 13.1.2 subscription. The perpetual versions can be standard or extended Photoshop wher the subscription version is Photoshop extended.

Similarly, there are several version of Photoshop Elements. All versions of the item not a lot of features that Photoshop in general. Its much cheaper and it has a lot less function then Photoshop. For many elements has all of the features they want. It is unless we learn and element has some hand holding the built-in feature for the novice user, which is something that Photoshop does not...

How to find the difference between two dates in time except Sunday

Hi all

I have a table, as shown below.

SQL> select * from test;

TR_ID                                              CREATE_TIME                                                                       CODE
-------------------------------------------------- --------------------------------------------------------------------------- ----------
S12341                                             05-JUN-12 12.20.52.403000 AM                                                      1003
S12342                                             11-JUN-12 11.15.33.182000 AM                                                      1003
S12342                                             07-JUN-12 12.00.36.573000 PM                                                      1002
S12343                                             20-JUN-12 12.34.37.102000 AM                                                      1003
S12343                                             15-JUN-12 11.34.27.141000 PM                                                      1002
S12344                                             01-JUL-12 10.01.06.657000 PM                                                      1002
S12344                                             06-JUL-12 12.01.04.188000 AM                                                      1003
S12341                                             31-MAY-12 11.20.38.529000 PM                                                      1002

I would like to know the difference between same tr_ids create_time, which should give out in hours except Sunday.

For example:

TR_ID: S12344
1002_Create_time: July 1, 12 PM 10.01.06.657000 (i.e. Sunday)
1003_Create_time: 12.01.04.188000 AM 6 July 12

1002 create time is 22:00 Sunday.

If the query must exclude only the hours of Sunday which is 10 p.m. to Monday 00 h which is 2 Hrs.

I tried the sub query after doing a search on this forum but I am not getting the desired output.

SELECT count(*) FROM (SELECT ROWNUM RNUM,tr_id,create_time CT_1002 FROM test c WHERE c.tr_id='S12344' and 
ROWNUM <= (select (cast(a.create_time as date)-cast((select create_time from test b where a.tr_id=b.tr_id and code=1002) as date)) 
from test a where a.code=1003 and a.tr_id=c.tr_id) + 1) d 
WHERE to_char(cast((select create_time from test e where e.tr_id=d.tr_id and code=1002) as date) + RNUM - 1, 'DY') NOT IN('SUN');

Need help to get the desired o/p

Hello

If I unederstand the problem correctly, that's what you want:

WITH       got_extrema     AS
(
     SELECT       tr_id
     ,       CAST (MIN (create_time) AS DATE)     AS start_date
     ,       CAST (MAX (create_time) AS DATE)     AS end_date
     FROM       test
     GROUP BY  tr_id
)
SELECT       tr_id
,       start_date, end_date          -- If wanted
,       24 * ( ( ( TRUNC (end_date,   'IW')          -- Count -1 day for every full week
                    - TRUNC (start_date, 'IW')
             )
           / -7
              )
            + LEAST ( end_date               -- If end_date is a Sunday
                        , TRUNC (end_date, 'IW') + 6     -- consider it 00:00:00 on Sunday
                 )
            - CASE
                      WHEN  start_date >= TRUNC (start_date, 'IW') + 6     -- If start_date is a Sunday
               THEN  TRUNC (start_date, 'IW') + 6               -- consider it 00:00:00 Sunday
               ELSE  start_date
                  END
            )     AS total_hours
FROM      got_extrema
;

I guess that you don't need to worry about fractions of a second. As you did in the code you have posted, I am to convert the TIMESTAMP to date values, because of DATE arithmetic and functions are so much better than what is available for timestamps.

Basically, it's just to find the number of days between start_date and end_date and multiplying by 24, with these twists:
(a) 1 day is deducted for each week between start_date and end_date
(b) if End_date is a Sunday, none of the end_date himself hours are counted
(c) If start_date is a Sunday, then all the start_date himself hours are counted. Why these hours should be counted? Because 1 day is already being deducted for the week which includes start_date, which contains only this Sunday.

TRUNC (dt, 'IW') is the beginning of the ISO week containing dt; in other words, 00:00:00 the or before the dt last Monday. This is not the NLS parameters.

Of course, I can't test without some sample data and the exact results you want from these data. You may need a little something more If start_date and end_date are both on the same Sunday.
Whenever you have a problem, please post a small example of data (CREATE TABLE and only relevant columns, INSERT statements) of all of the tables involved.
Also post the results you want from this data, as well as an explanation of how you get these results from these data, with specific examples.
Always tell what version of Oracle you are using.
See the FAQ forum {message identifier: = 9360002}

Difference between flow and stolen
Hello
can you please tell me difference between flow and stolen

Thank you
Nirmal
See: http://docs.oracle.com/cd/B31017_01/integrate.1013/b28981/parallel.htm

flow will be to use a pre-defined () amount of branches, with flight you can do the amount of dynamic branches

So let's say we have

getUserDetails
getAddressDetails

now, you can use streams, create 2 branches and make the call to both methods in each branch.

Let's say that you receive a list of customers in your service interface. Now, you can loop through with-foreach each customer and sequential not logic like Getcustomerdetails in the loop, or... .you create a flight and N is the number of clients in the list.

After that, you will get N parallel branches that will make Getcustomerdetails (instead of the other sequential loop)

This fly is the dynamic Variant that will create N branches according to the Counter field you base your expression on

Difference between Oracle versions!

Hello
I would like to know the difference between versions of oracle from oracle 7.
Also would like to know a way to understand the particular function works in version oracle x but not before version x.

for example. listagg function came in oracle 11.

Is there a link where I can find it and consolidated in one place.

Hello

923808 wrote:
Hello
I would like to know the difference between versions of oracle from oracle 7.
Also would like to know a way to understand the particular function works in version oracle x but not before version x.

for example. listagg function came in oracle 11.

LISTAGG was back in 11.2, to be exact.

Is there a link where I can find it and consolidated in one place.

Not that I know of.

From Oracle 9, there is a 'What's new' manual with all versions. For example:
http://docs.Oracle.com/CD/B10501_01/server.920/a96531/TOC.htm
Also from Oracle 9, most commonly used textbooks have a "What's New" section to the beginning:
http://docs.Oracle.com/CD/B10501_01/server.920/a96540/wnsql.htm#971925

Here is a list I made for my personal use:

Index of Features, showing when they were introduced into Oracle

ADD_MONTHS Function                    6.0     or earlier
Aggregate functions, user-defined          9
ALTER TABLE x RENAME COLUMN a TO b;          9.2
Analytic Functions                    8.1
     IGNORE NULLS                    10
APPEND, SPOOL                         10

BINARY_INTEGER same as PLS_INTEGER          10.1     http://download.oracle.com/docs/cd/B19306_01/appdev.102/b14261/datatypes.htm#sthref690

CASE Expressions                    8.1
CLOB Datatype                         8.1     or earlier     max size=4G in versions 8.1 and 11.2
COLUMN ... FOLD_AFTER (or FOLD_BEFORE)          8.1     or earlier
Conditional Compilation of PL/SQL          10.1.0.4
CONNECT BY                         2
     CONNECT_BY_ISCYCLE     pseudo-column     10
     CONNECT_BY_ISLEAF     pseudo-column     10
     CONNECT BY NONCYCLE               10
     CONNECT_BY_ROOT          operator     10
     LEVEL <= x (for Counter Table)          8.1.7.4     Re: Oracle Virtual Machine Connect by Prior Problem
     ORDER SIBLINGS BY               9
     Subquery in START WITH clause          9.2     or earlier
     SYS_CONNECT_BY_PATH     function     9

DATE between 4713 and 9999               8
DATE Literals                         10
DBMS_Metadata                         9
DBMS_RLS                         8.1
DBMS_SCHEDULER                         10
DELETE in MERGE                         11.1

EXTRACT                              9

FIRST Function                         9
FOLD_AFTER (FOLD_BEFORE) in SQL*Plus COLUMN     8.1     or earlier
Foreign Key Constraints                    7     (very limited enforcement in 6)
Functions, User-defined                    7
     Aggregate                    9

GREATEST Function                    6.0     or earlier

IGNORE NULLS
     in FIRST_VALUE, LAST_VALUE          10
     in LAG                         11.2
In-Line Views                         8.0     (documented in 8.1)

KEEP (DENSE_RANK ...)                    9

LAST Function                         9
LEAST Function                         6.0     or earlier
LISTAGG                              11.2
LNNVL Function                         10

MEDIAN Function (Aggregate or analytic)          10
MERGE                              9
MERGE ... DELETE                    10.1
MODEL                              10
MONTHS_BETWEEN Function                    6.0     or earlier

NEW_TIME Function                    6.0     or earlier
NOCYCLE, CONNECT BY                    10
NTH_VALUE Function                    11.2
NULLIF Function                         9

ORDER BY in Sub-Queries                    9
ORDER SIBLINGS BY                    9
OWA_Pattern Package (for Regular expressions)     9

Partioned Outer Joins (Query Partitioning)     10
PERCENT_RANK function                    8.1
PIVOT                              11
PLS_INTEGER same as BINARY_INTEGER          10.1     http://download.oracle.com/docs/cd/B19306_01/appdev.102/b14261/datatypes.htm#sthref690
Policies, Row-Level Security               8.1
PURGE                              10     

Q-Notation for string literals               10
Query Partition                         10

Read Consistency                    4
Recursive subqueries                    11.2
Regular Expressions                    10
     expr argument (_INSTR and _SUBSTR)     11.1
     OWA_PATTERN Package               9
Row-Level Security Policies               8.1

Scalar Sub-Queries (except in WHERE, etc.)     8.1     not documented until 9.1
SPOOL ... APPEND                    10
STATS_x Functions (Incl. STATS_MODE)          10
SYS_CONNECT_BY_PATH                    9
SYS_CONTEXT                         8.1     USERENV introduced in 8.0?
SYSDATE as Function                    6.0 ?     (It was a pseudo-column in PL/SQL 1.0, 1989.  6.0 SQL Language manual (1990) calls it a function.)

Triggers                         7

User-Defined Functions                    7
     Aggregate                    9
USERENV Function                    8.0?     Expanded to SYS_CONTEXT in 8.1
UTL_Match Package                    11.2     In Packages and Types manual

Virtual Columns     in tables               11
VPD ("Virtual Private Database")          8.1

WIDTH_BUCKET Function                    9
WITH Clause                         9
     Recursive                    11.2

XML                              9
XMLAGG Function                         9.2      (not in 9.1 SQL Language manual)
XMLELEMENT Function                    9.2      (not in 9.1 SQL Language manual)
XMLQUERY                         10

Published by: Frank Kulash, 28 March 2012 18:44

What is the difference between the sql statement
What is the difference between below sql statements, get the output of these statements

In the test table will have 55 columns

Select count (*) from test_table

Select count (1) into test_table

Select count (10) into test_table

Select count (100) in test_table

Select count (100000) into test_table

Thank you

Published by: Balajiraam on December 28, 2011 20:51

Published by: Balajiraam on December 28, 2011 21:02
Hello
This will be useful for you

http://asktom.Oracle.com/pls/asktom/f?p=100:11:0:P11_QUESTION_ID:1156151916789 #25335122556076

Kind regards
Fame

Difference between count (*) &amp; count (1)

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Difference between count (*) & count (1)