Remove Duplicate From Columns in Microsoft Excel

Today, I learned something interesting which I would like to share across to the readers. This is about eliminating duplicates from a column in an Excel workbook. The Spread sheet contained a column with 1000 odd rows and the challenge was to remove the duplicates and copy the unique rows to a different column. Most of you who would be reading this post would have encountered similar requirements and hope this post guides to get rid of identical values from a given worksheet. The test data we will be using for this exercise is provided below:

Assuming that these are placed in H8:H24 in a worksheet, the steps to eliminate duplicates are as below.

1) Select Data –> Sort & Filter –> Advanced. Following dialog box will be presented

2) Make sure that the following options are selected

a) “Copy to another location” is selected

b) “Unique Records Only” is checked.

3)In the “List Range” enter the range of values that needs to be filtered. For our example, we will be entering $H$8:$H$24

4) In the “Criteria Range” enter the same range of values i.e. $H$8:$H$24

5) In “Copy to”, specify a cell from where the unique values needs to be listed. Make sure you specify a dummy range area, else any existing values could get overwritten.

6) A completed example is shown below

7) Hit “OK”.

8) That is it..we are done..If you have followed the steps correctly, in the column Q the final filtered output would look like the one shown below


That concludes our simple example of eliminating duplicates from a list of values in Microsoft Excel.

List Folder Contents in Java

Often Java Developers stumble across a simple situation and end up googling the web to find the best code which can help to solve their needs. One such situation is - How to write a simple java program that lists the contents of a folder. There are quite a lot of solutions available for this, but I would like to post a working solution which can sometime prove really handy in solving the question. Next time you want to list the contents of a directory and are after a java code, check out in thinktibits..

Code:

-----

import java.io.File;
public class save{
    public void showDirectoryList() {
        File dir = new File("C:/temp");
        File[] list = dir.listFiles();
        for (int i=0; i
            if (list[i].isFile()) {
                System.out.println("File "+list[i].getName());
                } else if (list[i].isDirectory()) {
                System.out.println("Directory "+list[i].getName());
            }
        }
    }
    public static void main (String args[]) {
        save s = new save();
        s.showDirectoryList();
    }
}

Common PeopleSoft Integration Broker Issues–Part 6

Other Possible Problems

1. Problem: Can’t see Messages in Message Monitor

Possible Causes:  
I. Channel Security not set.
II. Message Monitor view criteria is too limiting (looking at the wrong time, channel, node, etc.)
Actions:  Take corrective measures.

2. Problem: My Publish() PeopleCode finishes successfully, but there is no message in the Message Monitor.
Possible Causes:
I. The Message Definition is InActive.
Actions:  Take corrective measures.

3. Problem: Message Instance sits in NEW status.
Possible Causes:
1.   Application Server down.

II. Pub/Sub services not configured on Application Server domain.
III. Message Broker Dispatcher down.
Actions:  Check pub/sub services and reboot them if necessary.

4. Problem: Message Instance sits in WORKING status.
Possible Causes:
I. Message Broker Handler crashed.
Actions:  Take corrective measures.
Resolution of Messages with Error status
1. From Sub Contracts Page, click on details for message in Error status.
2. Next, click on the Message Errors tab and check the Error Message
3. If the Error Message does not imply a solution then check on the app server log file for error message details, at /ps/c1prd/appserv/C1PRD/LOGS/APPSRV.LOG
For example:
· PSSUBHND_dflt.1169 [08/15/01 08:00:14 SubConProcess](1) GenMessageBox(6540, 11, M): Component Processor: Warning -- Address should consist of at least Street and City. (6540,11)
· PSSUBHND_dflt.1169 [08/15/01 08:01:25 SubConProcess](1) GenMessageBox(200, 0, M): /ds3/home/build81/pt81410rc6-retailr_o/src/psppr/ramget.cpp: SQL error. Stmt #: 609  Error Position: 0  Return: 8118 - Memory allocation failed (SQLSTATE PS118)
· PSSUBHND_dflt.1169 [08/15/01 08:01:25 SubConProcess](1) GenMessageBox(200, 0, M): SQL Access Manager: SELECT COUNTRY, DESCR, ADDR1_LBL, ADDR1_AVAIL, ADDR2_LBL, ADDR3_LBL, ADDR4_LBL, CITY_LBL, CITY_AVAIL, NUM1_LBL, NUM2_LBL, HOUSE_TYPE_LBL, ADDR_FIELD1_LBL, ADDR_FIELD2_LBL, ADDR_FIELD3_LBL, COUNTY_LBL, STATE_LBL, POSTAL_LBL, POST_SRCH_AVAIL, GBSYS_NRPATH_UK, GBSYS_CFGPATH_UK FROM PS_COUNTRY_TBL WHERE COUNTRY=:1 ORDER BY COUNTRY
· PSSUBHND_dflt.1169 [08/15/01 08:01:25 SubConProcess](1) GenMessageBox(200, 0, M): /ds3/home/build81/pt81410rc6-retailr_o/src/psapmsg/logerror.cpp: SQL error. Stmt #: 628  Error Position: 0  Return: 8118 - Memory allocation failed (SQLSTATE PS118)
· PSSUBHND_dflt.1169 [08/15/01 08:01:25 SubConProcess](1) GenMessageBox(200, 0, M): SQL Access Manager: SELECT MAX(SEQNO) FROM PSAPMSGSUBCERR WHERE PUBNODE = :1 AND CHNLNAME = :2 AND PUBID = :3 AND MSGNAME = :4 AND SUBNAME = :5
4. In this case, we resubmitted the message (see step#1 for Resubmit button) and it later successfully processed.
SQL and PC Trace options for App Server - good for checking if SQL events didn't take place or if Subscription PC didn't fire properly.

SQL Tracing on App Serv :In the AppServer Configuration file you can set the trace options.

Trace
After you have set the Domain Settings the Trace section appears. This section allows you to specify the tracing options that you can enable on the application server to track the SQL and PeopleCode of your domain(s).
Values for config section - Trace
    TraceSql=0
    TraceSqlMask=12319
    TracePC=0
    TracePCMask=4095
    TracePPR=0
    TracePPRMask=4095
    TraceAE=0
    Write crash dump to separate file=Y
Do you want to change any values (y/n)? [n]:
TraceSQL
Sets logging level for SQL tracing for all clients. Traces are written to the following location: <PS_HOME>/appserv/<domain>/LOGS/<DomainOPRID>_<svrname>.tracesql.
If you enter 0 it disables tracing; use 7 to enable a modest tracing level for debugging. For other levels of tracing, set to a value equal to the sum of the desired options. For example, if you only want to trace SQL, TraceSQL=1; if SQL statements and Connect statements are desired, TraceSQL should be set to 1+ 2 + 4 = 7. A setting of TraceSQL = 7 is recommended for troubleshooting connection and other basic problems. Tracing can consume large amounts of disk space over time so be sure to reset TraceSQL = 0 when you've finished trouble shooting.
TraceSQLMask
Sets logging level ceiling for SQL tracing for individual clients. Traces are written to the following location: <PS_HOME>/appserv/<domain>/LOGS/<ClientOPRID>_<svrname>.tracesql. Clients must specify desired SQL tracing level using PeopleSoft Configuration Manager on the Trace tab. To prevent clients from turning on the application server trace, and consuming resources, the application server uses TraceSQLMask as an administrative control facility.
If a client transmits a request to trace SQL, the application server compares the value transmitted to TraceSQLMask. If the client value is less than or equal to TraceSQLMask, the application server enables the trace. However, if the client value is greater, application server will enable the trace up to the TraceSQLMask value. Trace files are written on the application server; no trace shows up on the client workstation.
Trace values are set in the application server configuration file psappsrv.cfg file. Output files are written to directory $PS_HOME/appserver/winx86/<domain>/logs.
For TraceSQL and TraceSQLMask you have the following options:
1         - SQL statements
2         - SQL statement variables
4         - SQL connect, disconnect, commit and rollback
8         - Row Fetch (indicates that it occurred, not data)
16        - All other API calls except ssb
32        - Set Select Buffers (identifies the attributes of columns
            to be selected).
64        - Database API specific calls
128       - COBOL statement timings
256       - Sybase Bind information
512       - Sybase Fetch information
4096      - Manager information
8192      - Message Agent information
TracePC

Sets a desired level for PeopleCode tracing for activity generated by all clients on a domain. Eligible values will be defined in the configuration file. TracePC values are displayed in the Configuration Manager on the Trace tab. You can find the results in the following location: <PS_HOME>/appserv/<domain>/LOGS/<domain>.log.
TracePCMask

This parameter controls which of the PeopleCode Trace options requested by client machines will be written to the trace file. The results of this trace are written to
<PS_HOME>/appserv/<domain>/LOGS/<ClientMachine>.<domain>.log
For TracePC and TracePCMask you have the following options.
1         - Trace instructions
2         - List the program
4         - Show assignments to variables
8         - Show fetched values
16        - Show stack
64        - Trace start of programs
128       - Trace external function calls
256       - Trace internal function calls
512       - Show parameter values
1024      - Show function return value
2048    - Trace each statement in program
For the TraceSQL I would like for you to use a value of "5" and for the TracePC use a value of "10"

Common PeopleSoft Integration Broker Issues–Part 5

Access denied. No password defined on source message node.

Possible cause:
 
In 8.1x Source Message Node properties has entries in 'Password' and 'Re- verify Password'.
Solution: Blank these fileds and ping the source node it worked fine.


Page cannot be displayed message when attempting to bring up Gateway or gateway Administration page. 
 
Possible cause:
 
3. Make sure Apache/ Jserv started.
4. Make sure aliases are correct in zone.properties

Ping failed, Application server log message saying cannot find JVM.

Resolution:  The application server was on a different machine as the web server.  The Sun JRE 1.2 was downloaded on the web server machine.  Sun JRE 1.2 was re-downloaded on the application server machine and the setting JavaVM Shared Library in psappsrv.cfg file was set to point to the location of this JRE.

All attempted publishing messages from PIA resulted in the following error message

Resolution:  When the upgrade was performed to the production database the following people tool tables had no data in them. 
PSAPMSGPUBINST  (channel names and latest pubid)
PSAPMSGPUBCSYNC (channel names and update timestamp)
PSAPMSGPUBSYNC (channel names and update timestamp)
PSAPMSGSUBCSYNC (channel names and update timestamp)


Additional Notes:

1. Problem: Message instance/Publication Contract sits in NEW status for over 15 minutes with no other messages in progress.
 
Possible Causes:
I. Incorrect Gateway URL defined on Message Node.
II. Message nodes not used in any of the messages should not contain an URL. 
Example:  PSFT_CR which does not have an URL defined.
Actions:  Check URL on Gateway and ping message node.

2. Problem: Publication Contract sits in NEW status status for over 15 minutes with no other messages in progress.
 
Possible Causes:
 
I. Publishing Application Server down.
II. Publishing Pub/Sub processes not configured on App Server domain.
III. Message Channel Paused.
IV. Incorrect Gateway URL defined on Message Node.
V. Node paused.
VI. Previous Message had errors or timed out.
VII. No Publication PeopleCode exists, or PeopleCode is incorrect.
Actions:  Check listed system components, then resubmit message.

3. Problem: Publication Contract sits in WORKING status for over 15 minutes with no other messages in progress.
 
Possible Causes:
 
I. Single threading on the application server is making things slow…if the Pub/Sub processes are running
II. Pub/Sub processes not responding
Actions:  Add more handlers and reboot app server.

4. Problem: Publication Contract is in TIMEOUT status
 
Possible Causes:
 
I. Subscribing Application Sever down.
II. Subscribing Node is Paused.
III. Message Node URL is incorrect.
IV. No Subscription PeopleCode exists on Subscribing system, or Subscription PeopleCode is incorrect.
Actions:  Check listed system components, then resubmit message.

5. Problem: Publication Contract is in ERROR status
 
Possible Causes:
I. Message Node URL is incorrect.
II. Subscription PeopleCode is bad.
Actions:  Check listed system components, if fix is made then resubmit message.  Otherwise go to Resolution of Messages in Error status section.

6. Problem: Publication Contract is in RETRY status
 
Possible Causes:
III. “PS” Password changed on Gateway
Actions:  Check  ~/Gateway.administration and apply password updates to PS ID.

Subscription Process

1. Problem: Subscription Contract sits in NEW status for over 15 minutes with no other messages in progress.
 
Possible Causes:
 
I. Application Server down.
II. Pub/Sub processes not configured on App Server domain.
III. Message definition not active.
IV. Message channel paused.
V. Node paused.
VI. Previous Message had errors or timed out.
VII. If you’re missing a row in PSAPMSGSUBPRCID, do the following:
insert into PSAPMSGSUBPRCID values(0)  [This should never happen]
Actions:  Check listed system components.  Reboot Pub/Sub services if necessary.

2. Problem: Subscription Contract sits in STARTED status status for over 15 minutes with no other messages in progress.
 
Possible Causes:
 
I. Subscription Handler down
Actions:  Check listed system components, then resubmit message.

3. Problem: Subscription Contract sits in WORKING status status for over 15 minutes with no other messages in progress.
 
Possible Causes:
 
I. No Subscription PeopleCode exists
II. Subscription Handler crashed while processing message.
Actions:  Check listed system components.   Reboot Pub/Sub services if necessary.

4.Problem: Subscription Contract in ERROR status
 
Possible Causes:
 
I. Subscription PeopleCode errors.
II. Application Data errors.
Actions:  First resubmit message.  If it fails then go to” Resolution of Messages in Error status” section (below.)

5. Problem: Subscription Contract is in EDIT status

Possible Causes:
I. Message was edited and has yet to be resubmitted for processing.
Actions:  Normally this status only applies when an error is being reconciled by support personnel.

6. Problem: Subscription Contract is in RETRY status

Possible Causes:
I. Subscription PeopleCode is empty.
Actions:  This applies when a message has been resubmitted.

7. Problem: What happens when your message is routed to Both  (Publish & Subscribe) and the message instance is DONE, but  no subscription contract is created?   
Possible Causes:
I. Check your message subscription properties to make sure that the Local Publication ‘Invoke for local publication’ is turned on.
Actions:  This should never happen.  Escalate to IS support.

Common PeopleSoft Integration Broker Issues–Part 4

Subscription Contract stays in WORKING status.

Possible causes: 

1. The Subscription Handler has crashed or has been brought down. Check in Application Messaging Gateway Administrator
2. Also look for any errors in App Serv Log

Subscription Contract in ERROR status. 

 
Possible causes:
1. Subscription PeopleCode errors
2. Application data errors.

Subscription Contract in TIMEOUT status. 

 
Possible causes:

1.  Subscription PeopleCode errors
2.  If the message works sometimes, and sometimes does not this may be a problem with the application server configuration.  Tune up your application server min/max values, or reconfigure your domain to a medium or large domain.  Also, changing the recycle count for these services from 0 to 25,000 or 10,000 may eliminate this problem.

Integration Broker:  Unable to ping a node. 

 
Possible causes:

1. The web server for the Gateway is down.
2. The Gateway is not configured properly.
3. The app server for the node is down.
4. Verify url is correct. Copy url in browser address, should see "PeopleSoft <tools release> Application Messaging gateway".
       (note: be sure that url in the manage lookup contains // before an ip address or machine name)
NOTE: In PeopleBooks it is stated as "//http://HRMS-01/servlet/psft.pt8.gateway.GatewayServlet"
            it should read "http://HRMS-01/servlets/gateway"  notice the "//" are missing from the begining             and is should read "servlets" not "servlet"

Access denied, source node not found

..message even when source node defined on target database.
 
Possible cause:
1.  Known bug: Message Node caching not working.  If a new node is added, reboot appserver.

Integration Broker:  "Bad Gateway, General Exception error .." message when pinging node.

Possible cause:
1. Check Oprid/ Password of node on Configuration Servlet page. (http:// ?/servlet/gateway.administration)

Common PeopleSoft Integration Broker Issues–Part 3

Publication Contract stays in RETRY status

Possible cause:
1. The remote node cannot be "pinged" successfully.  The publication contract will be processed when the remote node comes back up.
2. No publication handler available, either because it's crashed or it has been brought down.

Publication Contract stays in WORKING status

Possible cause:
1. The publication handler processing the contract is on another machine and either the machine or the domain is down. Processing should continue when the pub/sub system on the other machine comes back up.

Subscription Contract not created.

Possible causes:
1. Message Subscription is inactive.
2. Channel routing rules not set up properly.

Subscription contract - Local Node Issue

For a message published by the local node, subscription contract not created for local node even when Message Subscription is active and "Invoke for local publication" is checked.


Possible cause:
1. The local node was not included in the routing rules for the channel.  To subscribe to its own publications, the local node must be included in the channel routing rules.

Subscription Contract stays in NEW status.

Possible causes:
1. The Subscription Dispatcher has crashed or has been brought down.
2. Message Channel Node or System paused.
3. Message Definition not Active.
4. Previous message had a status of RETRY, ERROR, or TIMEOUT.
5. The Subscription contract is not at the top of the queue.  All Subscription Contracts with the same Channel/ Subchannel and subscription owner are in the same queue.

All publication Contracts remain in a NEW status.

Resolution:  The queue was blocked from a Publication Contact that was in a status of ERROR from two weeks prior.  User did not see the error on the message monitor because he was only looking at today.  User entered xx day in and the ERROR publication appeared.  Canceled the error and all subsequent publication contracts processed successfully.   

Subscription Contract stays in STARTED status.

Possible causes:
1. The Subscription Handler has crashed or has been brought down.

Common PeopleSoft Integration Broker Issues–Part 2

Integration Broker: Message Instance stays in STARTED status.

Possible cause: 

1. All Message Handlers have crashed or have been brought down. Processing will resume when Message handlers come brought back up 

2. The Message dispatcher processing the message is on another machine, and either the machine or the application server domain is down. 

Integration Broker: Message Instance stays in WORKING status.

Possible cause:

1. Message Handler has crashed. 

2. The Message Handler processing the message is on another machine, and either the machine or the application server domain is down.  The Message handler working on the message is "blocked". The service will timeout, and the Message Dispatcher will retry the message.

Publication Contract not created

Possible cause:

1. Channel routing rules not set up properly. 

Publication Contract stays in NEW status

Possible cause: 

1. Publication Dispatcher has crashed or has been brought down. 

2. Message Channel paused. 

3. Node paused 

4. Previous message had a status of RETRY, ERROR, or TIMEOUT.  

5. The Publication Contract is not at the top of the queue.  All Publication Contracts with the same Channel/ Subchannel and subscribing node are in the same queue

Common PeopleSoft Integration Broker Issues–Part 1

Integration Broker:  Cannot find message Message Monitor

Possible causes:

1. User does not have security for the message channel.
2. The message monitor criteria have filtered out the message.

Integration Broker:  Messages processed in incorrect order

Possible cause:

1. The Channel has been partitioned, and the resulting subchannels do not match what was assumed for the ordering of the messages.

Integration Broker: Message Instance not created

Possible cause:
1. Message is inactive.

Integration Broker: Message Instance stays in NEW status.

Possible cause:
1. The pub/sub servers are not booted.
2. The Message Dispatcher has crashed or has been brought down.
3. The Item is not at the top of the queue.  All messages with the same Channel/ Subchannel are in the same queue
4. Run appmsgpurgeall.dms
5. Restart PUBSUB processes
6. Force cleanup from the monitor message -> domain status
7. Test your message by routing it through another channel to make sure that it is not an issue with the channel.

PSAPPSRV list of Services

Some time back, tried to get a comprehensive list of services available for usage by the PSAPPSRV process in the application server..And the result, amazing..

SqlQuery     SqlRequest   PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
ICQuery      ICQuery      PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
GetDebugPar+ GetDebugPar+ PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
SamGetParms+ SamGetParms+ PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
StmGetTimeO+ StmGetTimeO+ PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
StmChgPswd   StmChgPswd   PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
SqlRequest   SqlRequest   PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
RamList      RamList      PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
GetWebProfi+ GetWebProfi+ PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
Template     Template     PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
HomepageT    HomepageT    PSAPPSRV   APPSRV     1   <your server>       5 AVAIL
FileAttach   FileAttach   PSAPPSRV   APPSRV     1   <your server>       1 AVAIL
ICLifeEvent  ICLifeEvent  PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
ICWorkList   ICWorkList   PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
ICNav        ICNav        PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
ICScript     ICScript     PSAPPSRV   APPSRV     1   <your server>      11 AVAIL
ICPanel      ICPanel      PSAPPSRV   APPSRV     1   <your server>      44 AVAIL
WsrpPortlet+ WsrpPortlet+ PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
JavaPortlet+ JavaPortlet+ PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
KeyStore     KeyStore     PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
PortalRegis+ PortalRegis+ PSAPPSRV   APPSRV     1   <your server>       7 AVAIL
PSBusInterl+ PSBusInterl+ PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
Integration+ Integration+ PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
PSBusComp    PSBusComp    PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
PSSession    PSSession    PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
GetCertific+ GetCertific+ PSAPPSRV   APPSRV     1   <your server>       4 AVAIL
RenRequest   RenRequest   PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
McfChkAttAu+ McfChkAttAu+ PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
PpmMonSvc    PpmMonSvc    PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
PubContract  PubContract  PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
SubContract  SubContract  PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
GetPub       GetPub       PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
CancelPub    CancelPub    PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
ResubmitPub  ResubmitPub  PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
UpdatePubDa+ UpdatePubDa+ PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
Publish      Publish      PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
OpnQryExecu+ OpnQryExecu+ PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
OpnQryDescr+ OpnQryDescr+ PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
TdmUtilSvc   TdmUtilSvc   PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
StmGetExpla+ StmGetExpla+ PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
RemoteCall   RemoteCall   PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
QdmGetListS+ QdmGetListS+ PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
PsdGetListS+ PsdGetListS+ PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
GetAppImages GetAppImages PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
PsmChkUserR+ PsmChkUserR+ PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
PsmChkRptAu+ PsmChkRptAu+ PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
PprPrePopup+ PprPrePopup+ PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
PprMItemSel+ PprMItemSel+ PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
PprSecStart  PprSecStart  PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
PprSearchSa+ PprSearchSa+ PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
PprSearchSt+ PprSearchSt+ PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
PprDeleteRow PprDeleteRow PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
PprInsertRow PprInsertRow PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
PprDefault   PprDefault   PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
PprFieldCha+ PprFieldCha+ PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
PprChangeVa+ PprChangeVa+ PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
PprFullSave  PprFullSave  PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
PprSave      PprSave      PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
PprLoad      PprLoad      PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
ObjectAccess ObjectAccess PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
MgrReplayCa+ MgrReplayCa+ PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
MgrUpdObject MgrUpdObject PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
MgrGetObject MgrGetObject PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
MenuList     MenuList     PSAPPSRV   APPSRV     1   <your server>       0 AVAIL
JavaMgrGetO+ JavaMgrGetO+ PSAPPSRV   APPSRV     1   <your server>       0 AVAIL

Oracle Concepts Course - Part 1

I'm a great fan of Dizwell and have saved some of his valuable articles when I first saw them in the web. I'm posting it here so that the entire community can read through it and get the basics right.

Courtesy: Dizwell the great..

What is an Oracle Server?

When you edit a document in Word (or whatever word processor you happen to prefer!), you don't type documents directly into a disk file, because doing so would be painfully slow. Instead, documents are initially 'typed into' and created in memory -your computer's RAM- because that works at nanosecond speed and is thus very fast and responsive to work with. Unfortunately, most of today's RAM is volatile: switch off the computer's power supply and you lose the lot -and if you've ever been typing a long, complicated document and had a power cut before you remembered to save it, you'll know the sinking feeling of your brush with volatility!

To protect against data loss like that is why you're supposed to do a periodic 'File -> Save', of course. Hard disks might be slow and painful to use for constant access, but they make a fine permanent store of things which have initially been created and worked on in RAM. Saving a document in Word simply means 'transfer a copy of it out of volatile memory and onto permanent disk storage'. In this way, your word processor lets you combine the speed of RAM with the permanence of hard disk storage. You therefore end up getting the best of both worlds: speed and safety.

In fact, that goes for any program you care to mention, be it a word processor, a video editing package, a media player, whatever: data is read from its permanent store on hard disk and manipulated and worked on in memory, because one is fast but volatile and the other is slow but safe.

The Oracle Relational Database Management System (RDBMS) is just another program in this respect, because it does exactly the same thing. The data it manages is stored permanently on disk but when someone wants to update it, view it or delete it, it is loaded from disk into memory and it is in memory that all the data manipulation takes place. The permanent store of data on disk is what we call the Oracle database. The chunk of RAM where the database's data is actually worked on is called the Oracle instance. 

The relationship between an instance and a database is one-to-one: if an instance has accessed the data from database X, it cannot also access or work on the data from database Y. If you want to work with the data from database Y, you will need to use another instance entirely. This relationship -one instance manages only one database- is always and completely true.

The relationship the other way around is not always like that, though. In an advanced configuration of Oracle known as a Real Application Cluster (or RAC for short), it is possible for one database to be accessed by two or more instances, simultaneously. That's usually done to speed things up and get more work done. But even so, each of the participating instances in a RAC can only be used to store and work on data from one database. So the rule can be more fully stated as:

one instance can only work on one database,
but one database may be opened by many instances

An Oracle Server is nothing more, therefore, than a computer onto which the Oracle software has been installed; on which an Oracle instance is running in memory (providing fast but volatile data management capabilities); and on which an Oracle database has been permanently stored on disk.

Users connect to the instance (not the database, note) and make requests to see or to manipulate data from the database by issuing SQL statements. In response to these SQL statements, the Oracle program loads the requested data into the instance. The user continues to work on the data within the instance. Occasionally, to make sure a power failure doesn't cause the loss of all the work users have been doing, the Oracle software performs, in effect, an automatic 'File -> Save' and writes the data stored in the instance back to the physical database on disk. In this way, users of an Oracle database get all the performance advantages of working with things in fast RAM, but all the permanence and safety advantages of having saved stuff to disk.