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Forum:
WinDev Forum
Beiträge im Thema:
7
Erster Beitrag:
vor 1 Jahr, 6 Monaten
Letzter Beitrag:
vor 1 Jahr, 6 Monaten
Beteiligte Autoren:
StanleyBarnett, Al, Ruben Sanchez Peña, Arie

Is HFSQL Client/Server File or Server Based?

Startbeitrag von StanleyBarnett am 07.07.2016 06:33

Hi,

I see that HFSQL Classic uses filesystem files like VFP does whereas the customer table would be represented as customer.fic on disk.

Does HFSQL Client Server save its tables in the database like MSSQL does where all the tables in the entire database is saved into MSSQL's .mdf file instead of individual filesystem files?

Thanks, Stanley

Antworten:

Hi. Classic and CS use the same files. Individual file for each table.

Rubén

von Ruben Sanchez Peña - am 07.07.2016 07:12
Stanley,

the files used are exactly the same.
In classic mode the app has access to the directly.
in hfcs mode the app is talking to a service (over tcpip), which in turn has access to those files.
You cannot use both methods on the same datafiles (I dont see why one want to). hfcs is locking the files exclusively

von Arie - am 07.07.2016 07:48
Hi Ruben and Arie,

Thanks Arie for your detailed explanation of how the structures work because I was about to reply to Ruben's message asking how the data can be seen by other and remote computers as well as permissions and security at the filesystem, user, and server levels.

Does the HFSQL model support granular security support such as that of MSSQL where reads, writes, and viewability can be granted or denied based on user, device, OUs, and/or groups?

Thanks again, Stanley

von StanleyBarnett - am 07.07.2016 15:00
Hello Stanley

If you open the HyperFile Control Centre you can see the security options and try them out for yourself.

Regards
Al

von Al - am 07.07.2016 16:11
Thanks Al, I spent some time there and looks like it covers the basics compared to MSSQL which is good.

Thanks, Stanley

von StanleyBarnett - am 07.07.2016 16:57
Hello Stanley

My approach to HFCS is to regard it as a wrapper around a set of HF Classic files.
If the files are being used in Classic mode then the application has direct access to the files. In HFCS access to the same files is managed by the HFCS engine but there is no difference in the actual data file between HFCS and Classic.

However there are some things to keep in mind regarding how you access the files as it does depend on the backend you are using.
In Classic you can use a step though approach to getting data.
Hfilter(DataFile,Index)
Hreadfirst(dataFile,Index)
While not Hout(DataFile)
Do something with the record
Hreadnext(DataFile,Index)
End

Or you can use queries and views.

In HFCS you can still do the same things but you are better off using queries wherever possible because it is one request to the HFCS engine to assemble the data and deliver it back where the step through approach will do a request for every Hread statement so much more traffic on the network.

I think it is quite a good approach by PCSoft. It maintains backwards compatability and it allows developers access to both types of data with the same code so you can tailor your development between small and larger users.
Switching between the two data access methods is just a few lines of code and these are generally in an ini file


Regards
Al

von Al - am 07.07.2016 23:28
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