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Larry Hengen

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Larry Hengen last won the day on April 18

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  1. Larry Hengen

    Best Practices for FireDAC FetchMode/RecordCount Settings

    @Hans J. Ellingsgaard I am using SQL Server. The query uses an inner join on about 5 tables, a left outer on one and a cross apply with a group by and order by on the results Pretty much a worst case scenario. Some of the criteria is not indexed, and due to the data layout requires a large # of reads. Some work has been done on the query to optimize it, and it's now better, but the question remains; what are the best settings to use for FireDAC when the cost and row count of a particular query is not generally known at design-time, as is the case with many dynamically built SQL queries.
  2. Larry Hengen

    Best Practices for FireDAC FetchMode/RecordCount Settings

    I beg to differ. The situation I encountered was that a very expensive SQL Server query wrapped in a select count(*) from() was causing major performance issues. Result set was about 1500 rows. In this case I think it's far easier to bring back the entire result set. What I was looking for was guidelines other devs are using to make such decisions since the actual row counts are not well known.
  3. Larry Hengen

    Best Practices for FireDAC FetchMode/RecordCount Settings

    That is exactly what FireDAC does for you so why would I write additional code to do the same thing? I want to avoid a second query because it can be detrimental to your SQL back end's performance. Imagine doubling it's workload for every user... A less intensive approach is to fetch all records, but that can cause a delay in processing while they are streamed to the client, and if the query is in the main thread, the application will "freeze".
  4. I have recently encountered a situation where code was explicitly setting queries to use FetchOptions.RecordCountMode := cmTotal. The query involved was rather complex and therefore expensive to execute and due to the RecordCountMode set, was being executed twice as per the FireDAC Documentation. As a result, together with all the other workload it was bringing SQL Server to it's knees. That got me thinking about what are appropriate (read least resource utilization with best performance) settings to use in the following scenarios: 1) You open a query to gather data and iterate over each record not updating the record itself but perhaps issuing other SQL Statements., or generating a report -such a query could be ReadOnly, ForwardOnly 2) You open a query with RequestLive = True and iterate over it updating values which FireDAC posts back to the database In both of the scenarios above, to display progress information you want the total record count. What do developers usually use for FireDAcC FetchMode/RecordCountMode and other settings in such scenarios and what if any combination of settings are done globally with a TFDManager vs. locally at the query level?
  5. Larry Hengen

    Issues Deploying Firebird DB on Ubuntu 8.04LTS

    I reported this as RSP-30899 and posted on the Firebird support forums as well asking for a workaround.
  6. Larry Hengen

    Issues Deploying Firebird DB on Ubuntu 8.04LTS

    @Lars Fosdal I did try to change the database file permissions but the exception remains. The interesting thing is that I discovered the exception is not fatal. I previously assumed that once it was thrown the application could not continue. This is not the case. The application opens and does appear to behave normally. I can set a break point and debug the app, so the issue is not critical, but I would like to understand why an exception is thrown and resolve it. I have attached the DB permissions both before and after changing them. I noticed a status error opening the DB through isql about access to /tmp/Firebird so I changed the permissions on that folder. Now the exception is fatal :-). My conclusion is that I will have to post the exception on the Firebird forums for a developer to comment, or create a bug report if that doesn't work. Seems to be an installation issue of some sort. Thanks fro all the feedback.
  7. Larry Hengen

    Issues Deploying Firebird DB on Ubuntu 8.04LTS

    It's not that simple. I copied the DB to /home/larryh/Downloads/LinuxDBForCompositeTesting/COMPOSITEAPP.FDB but I get an exception (shown below) when FireDAC attempts to open the database when I am debugging. As I said, I can run the app fine from the command line, but that doesn't help me debug the app on Linux. The DB is owned by the Firebird Administrator. I have tried changing ownership to my account but that doesn't resolve the error. Project FmxTaskApp raised exception class N8Firebird16status_exceptionE with message 'Exception Object Address: 0x1C04280'.
  8. I experimented this weekend with deploying a small FMX app that uses a Firebird 3 database running on a Linux instance. From reading the DockWiki it doesn't seem to me that you can deploy a database file on Linux (through a VM shared drive mapping), and if you copy the database file on the linux side to the scratch folder, it is removed once you attempt to debug the application over PAServer. Is there a way to prevent PAServer from deleting files that are not part of the deployment but appear in the scratch-dir? For some reason I also cannot debug the application, I get an N8Firebird16status_exceptionE exception when attempting to open the database connection. The database file is present as I create it before the application attempts to open it. I can however, run the application from the terminal window. I assume it has something to do with permissions. PAServer is running under my user account and FireDAC is establishing a local connection to the database which is in the same folder as the app. It doesn't help using sudo to run PAServer, so I am at a loss...
  9. Larry Hengen

    Automated Way to Detect Interface Breaking Changes

    Thanks for the response and pointing me to Dependency Walker. As for the run-time packages, it's not my choice. I was asking about best practices because I have normally been using Monolithic EXEs. Didn't realize I was already using the best practices for package based apps ;-0
  10. If you have an application that uses run-time packages and are supporting an older release, you cannot change the interface of any package or you have to re-distribute all dependent packages instead just the one you're updating. Is there anyway to detect interface breaking changes automatically (that it could be put on a build server)? Any advice on maintaining apps using run-time packages?
  11. Larry Hengen

    Is quality.embarcadero.com down?

    It uses a the same authentication as edn.embarcadero.com which gives an error. Looks like the Oracle database is down or inaccessible: System.Web.Services.Protocols.SoapException: Server was unable to process request. ---> System.Data.OracleClient.OracleException: ORA-12514: TNS:listener does not currently know of service requested in connect descriptor at System.Data.OracleClient.OracleException.Check(OciErrorHandle errorHandle, Int32 rc) at System.Data.OracleClient.OracleInternalConnection.OpenOnLocalTransaction(String userName, String password, String serverName, Boolean integratedSecurity, Boolean unicode, Boolean omitOracleConnectionName) at System.Data.OracleClient.OracleInternalConnection..ctor(OracleConnectionString connectionOptions) at System.Data.OracleClient.OracleConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningObject) at System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnection owningConnection, DbConnectionPool pool, DbConnectionOptions options) at System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject) at System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject) at System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject) at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) at System.Data.OracleClient.OracleConnection.Open() at EDN.Data.DbUtils.CreateConnection(ConnectionStringSettings ASettings, Boolean AOpen) at EDN.Data.DbUtils.CreateConnectionName(String AName) at MembershipWS.CDNMemberService.get_LookupSvc() at MembershipWS.CDNMemberService.GetCountryStatus(String CountryCode) --- End of inner exception stack trace I let Jim McKeeth know. Hopefully that will spur resolution.
  12. Larry Hengen

    Delphi Rio IDE hangs again and again

    I always make sure the IDE AutoSave options for both Editor and Project are enabled and find that I compile often enough to validate my changes that loss of significant work is usually not a problem.
  13. Larry Hengen

    CalDavServer and Client

    Thanks for the links. From what I understand the TMS Cloudpack has a Synchronization component which I will have to investigate. As for Sabre, I ran into that in my google searches but I didn't think it would work for me as it's not a Delphi solution. Will look into it's plugins further...thanks all for your suggestions.
  14. Larry Hengen

    CalDavServer and Client

    Does anyone know of a good CalDAV server and client implementation for Delphi?
  15. Larry Hengen

    Profiler for Delphi

    I agree the price is quite reasonable. Not crazy about the UI, but it's usable. I have been trying to use the ProDelphi 64 bit profiler against a large project using many run-time packages that has lots of code in the DPR. I am not getting the body code profiled. Any tips? I am trying to profile performance from startup to the appearance of the main form including any calls into the run-time packages.
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