Re: [GENERAL] Can PostGreSQL handle 100 user database?
"LO" == Lamar Owen [EMAIL PROTECTED] writes: LO The 2GB size limits of ia32 come in to play due to byte addressing LO (versus word addressing) in ia32 plus the use of signed single register LO two's-complement integers. LO But, as always, I reserve the right to be wrong. You are wrong. The file size limit has to do with the data size of your file offset pointer. This is not necessarily a 32 bit quantity on a 32-bit processor. -- =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Vivek Khera, Ph.D.Khera Communications, Inc. Internet: [EMAIL PROTECTED] Rockville, MD +1-240-453-8497 AIM: vivekkhera Y!: vivek_khera http://www.khera.org/~vivek/
Re: [GENERAL] Can PostGreSQL handle 100 user database - more info
Replies inline. Adam Lang Systems Engineer Rutgers Casualty Insurance Company http://www.rutgersinsurance.com - Original Message - From: [EMAIL PROTECTED] To: "Adam Lang" [EMAIL PROTECTED] Sent: Thursday, November 30, 2000 12:40 PM Subject: Re: [GENERAL] Can PostGreSQL handle 100 user database - more info I am not sure what an ole db provider is? This must be another method of talking to the server from a client application. What advantages does it have? Yes. It is an abstraction layer, but it is Windows only technology. The way it works is that The database has an ole db provider (much like ODBC). ADO connects to the database using the ole db provider. You write your application using the ADO object model to interact with the database. Biggest advantage: as long as you have an ole db provider for that datasource, your ADO code is universal. Example. You have an application that connects to MS SQL Server using ADO and you extract data, run queries, etc. Later you migrate to Oracle. You change your connection string (which is one line) and in most cases, you can run your app without any other changes. ADO is also able to connect to non relational data sources: Text files, VSAM, AS/400, etc. Plus, the ole db provider should be made to expose the database schema... so you can manipulate data in an object oriented way, as well as poll the data source for structure information. A lot more information is at microsoft's website. Also, in a scenario where the data source does not have an ole db provider, there is one supplied that will connect through ODBC. I have the open source ODBC client (and I know a Java version exists), it seems ok but I don't know if it handles things like transactions and other advanced functions. If the ole db provider is made correctly, it should support anything that the database allows. I'm not too familiar with using the postgres ODBC driver. For the most part, I've come to the point where I have not really made too many VB apps with a postgres bckend, due to the fact I have to use the ODBC driver, which is a bit outdated (but it does work). It would obviously be important to have a good method of talking to P-sql from Windows since a lot of people will want to do this. That has been my argument that a good connection method is needed to get into the Windows arena. Windows developers are spoiled. No matter how much you want to bad mouth MS, they do give us some great development tools. Unfortunately, postgres doesn't have anything to woo any windows develoeprs over.
Re: [GENERAL] Can PostGreSQL handle 100 user database?
On Thu, Nov 30, 2000 at 01:48:43PM -0400, The Hermit Hacker wrote: Note that this is a Linux limitation ... and even then, I'm not quite sure how accurate that is anymore ... the *BSDs have supported 2gb file systems for ages now, and, since IBM supports Linux, I'd be shocked if there was a 2GB limit on memory, considering alot of IBMs servers support up to 4 or 8GB of RAM ... Correct. With the 36-bit PAE extensions on PII and above CPUs, Linux supports up to the full 64GB of physical RAM. Individual processes are limited to either 2GB or 3GB (or 3.5GB), depending on the kernel compile option as to the division point between kernel and user memory. Linux also supports 2GB files (the kernel is limited to 2TB IIRC -- 2^32 512 byte blocks). Of course, on a 64-bit CPU, all these limitations are off, which really makes them the platform of choice for heavy data manipulation (I/O). -- Bruce Guenter [EMAIL PROTECTED] http://em.ca/~bruceg/ PGP signature
Re: [GENERAL] Can PostGreSQL handle 100 user database?
On Thu, 30 Nov 2000, The Hermit Hacker wrote: Note that this is a Linux limitation ... and even then, I'm not quite sure how accurate that is anymore ... the *BSDs have supported 2gb file systems for ages now, and, since IBM supports Linux, I'd be shocked if there was a 2GB limit on memory, considering alot of IBMs servers support up to 4 or 8GB of RAM ... Linux 2.2.x on ix86 only supports files upto 2 GB. Linux 2.4.x or any 64-bit plateform (SPARC, Alpha, m68k) fixes this (through the Large File Summit support, and a new libc). Memory: Upto 1 GB is supported stock, 2 GB by recompiling kernel. There is work in progress in 2.4 for supporting the 32 bit ix86 addressing modes available in some processors.
Re: [GENERAL] Can PostGreSQL handle 100 user database?
Here is a link that explains memory. It is from a windows2000 magazine, but it isn't very NT specific. It speaks in genaralities. I thought it was a rather good atrticle. http://www.win2000mag.com/Articles/Index.cfm?ArticleID=7290 I don't think you need to be a subscriber to read it. Adam Lang Systems Engineer Rutgers Casualty Insurance Company http://www.rutgersinsurance.com - Original Message - From: "Vivek Khera" [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Thursday, November 30, 2000 1:31 PM Subject: Re: [GENERAL] Can PostGreSQL handle 100 user database? "LO" == Lamar Owen [EMAIL PROTECTED] writes: LO The 2GB size limits of ia32 come in to play due to byte addressing LO (versus word addressing) in ia32 plus the use of signed single register LO two's-complement integers. LO But, as always, I reserve the right to be wrong. You are wrong. The file size limit has to do with the data size of your file offset pointer. This is not necessarily a 32 bit quantity on a 32-bit processor. -- =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Vivek Khera, Ph.D.Khera Communications, Inc. Internet: [EMAIL PROTECTED] Rockville, MD +1-240-453-8497 AIM: vivekkhera Y!: vivek_khera http://www.khera.org/~vivek/
Re: [GENERAL] Can PostGreSQL handle 100 user database - more info
[EMAIL PROTECTED] wrote: I am not sure what an ole db provider is? This must be another method of talking to the server from a client application. What advantages does it have? If you intend to use ADO you need an OLE-DB provider. I have the open source ODBC client (and I know a Java version exists), it seems ok but I don't know if it handles things like transactions and other advanced functions. The ODBC midht cause some "interesting" trouble since VisualBasic tends to open multiple connections to the Server. This has tow disadvantages: 1. While using transaction isolation (not reading uncommitted data) you cannot read the data written on one connection over another one. If this does happen you might not immediately notive the rubbish happening. 2. With 100 users it might significant if there are 500 simultaneous connections open. At leas you have to raise the connection-limit. Elmar
RE: [GENERAL] Can PostGreSQL handle 100 user database?
Hi, 2Gb file *systems* have been supported forever and a day on Linux. ext2 supports this without batting an eyelid. 2Gb *files* have not been supported very well or very long on 32-bit systems. Essentially you need a recent 2.4.0-test kernel version (test7 and up) or a patched 2.2.x kernel (more likely if you're in a production environment). For more information, see http://www.suse.de/~aj/linux_lfs.html 2Gb memory is a limitation under x86 (ia32) Linux in current production kernels (2.2.x). Again, the new 2.4.0 kernels go one better by using Intel's PAE (Physical Address Extension) mode on Pentium Pro CPUs and newer. This raises the available memory on Linux to 64Gb. Of course, 2.4.0-testx kernels are not production quality, but it's a good taste of what's imminent. Hope this helps. Francis Solomon Note that this is a Linux limitation ... and even then, I'm not quite sure how accurate that is anymore ... the *BSDs have supported 2gb file systems for ages now, and, since IBM supports Linux, I'd be shocked if there was a 2GB limit on memory, considering alot of IBMs servers support up to 4 or 8GB of RAM ...
Re: [GENERAL] Can PostGreSQL handle 100 user database - more info
But there is an OLE DB provider for ODBC, so you can use ADO with an ODBC; just not as nice. As for the multiple connections thing, I do not know anything about that. Adam Lang Systems Engineer Rutgers Casualty Insurance Company http://www.rutgersinsurance.com - Original Message - From: "Elmar Haneke" [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Thursday, November 30, 2000 1:59 PM Subject: Re: [GENERAL] Can PostGreSQL handle 100 user database - more info [EMAIL PROTECTED] wrote: I am not sure what an ole db provider is? This must be another method of talking to the server from a client application. What advantages does it have? If you intend to use ADO you need an OLE-DB provider. I have the open source ODBC client (and I know a Java version exists), it seems ok but I don't know if it handles things like transactions and other advanced functions. The ODBC midht cause some "interesting" trouble since VisualBasic tends to open multiple connections to the Server. This has tow disadvantages: 1. While using transaction isolation (not reading uncommitted data) you cannot read the data written on one connection over another one. If this does happen you might not immediately notive the rubbish happening. 2. With 100 users it might significant if there are 500 simultaneous connections open. At leas you have to raise the connection-limit. Elmar
Re: [GENERAL] Can PostGreSQL handle 100 user database?
Marc SCHAEFER [EMAIL PROTECTED] writes: On Thu, 30 Nov 2000, The Hermit Hacker wrote: Note that this is a Linux limitation ... and even then, I'm not quite sure how accurate that is anymore ... the *BSDs have supported 2gb file systems for ages now, and, since IBM supports Linux, I'd be shocked if there was a 2GB limit on memory, considering alot of IBMs servers support up to 4 or 8GB of RAM ... Linux 2.2.x on ix86 only supports files upto 2 GB. This support has been backported as is available in some kernels shipped with Red Hat Linux, and has been so for some time. Possibly others. -- Trond Eivind Glomsrød Red Hat, Inc.
Re: [GENERAL] Can PostGreSQL handle 100 user database?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On Thu, 30 Nov 2000, The Hermit Hacker wrote: Note that this is a Linux limitation ... and even then, I'm not quite sure how accurate that is anymore ... the *BSDs have supported 2gb file systems for ages now, and, since IBM supports Linux, I'd be shocked if there was a 2GB limit on memory, considering alot of IBMs servers support up to 4 or 8GB of RAM ... Linux kernel 2.2.x unpatched has the 2GB file size and 1GB ram limit. Patched with the lfs package the 2GB file size limit goes away. The lfs patch needs applied against gnu-libc as well. This alone may not avoid the 2GB limit, the application must use the lseek64 instead of lseek, for example. lfs will be included by default in the upcoming 2.4.x kernels. The upcoming 2.4.x kernels also support more ram. I'm fairly certain ram patches exist for the 2.2.x series. I have just one question to ask will postgresql 7.1 include full support for using lseek64, stat64, etc? -BEGIN PGP SIGNATURE- Version: GnuPG v1.0.4 (GNU/Linux) Comment: Made with pgp4pine 1.75 iEYEARECAAYFAjomo5wACgkQwtU6L/A4vVD+bgCfZqBGG2C/FQceN4BkE9m474K1 mHcAoKEFHowB6iWhbOhPbOdDUxlN0eyA =/AV7 -END PGP SIGNATURE-
