Thread: postgresql newsgroups
My ISP's newserver carries the following postresql groups: comp.databases.postgresql comp.databases.postgresql.bugs comp.databases.postgresql.docs comp.databases.postgresql.hackers comp.databases.postgresql.patches comp.databases.postgresql.questions The trouble is that there are hardly any articles coming into these groups. Is the bulk of user generated information about postgresql in mailing lists? (I'm subscribe to too many already) I can't understand why there are so few messages about a free database package. And if this isn't too inflamatory a question, where does postgresql stand in comparison to MySql and DB2? (both of which aren't free I believe).
I agree completely. Also these group send back an email to posts that they don't reconize as coming from someone who as subscribed to the group which I have. There really doesn't seem to be enough posting to warrent all of those different groups. by the way, can i access my postgresql database using perl running on WinNT, how? thanks! On 17 Feb 2000 05:50:29 +1050, jamesbinary@icqmail.com (James) wrote: >My ISP's newserver carries the following postresql groups: > >comp.databases.postgresql >comp.databases.postgresql.bugs >comp.databases.postgresql.docs >comp.databases.postgresql.hackers >comp.databases.postgresql.patches >comp.databases.postgresql.questions > >The trouble is that there are hardly any articles coming into these groups. > >Is the bulk of user generated information about postgresql in mailing >lists? (I'm subscribe to too many already) > >I can't understand why there are so few messages about a free database >package. > >And if this isn't too inflamatory a question, where does postgresql stand >in comparison to MySql and DB2? (both of which aren't free I believe).
> And if this isn't too inflamatory a question, where does postgresql stand > in comparison to MySql and DB2? (both of which aren't free I believe). > MySQL does NOT support transaction, which is indispensable for a real DBMS used as the primary data storage system for reliable/consistent business transactions. However, MySQL is the fastest RDBMS ever seen, and perfect for data warehouses and DSS and EIS purposes, as well as for query databases for web sites. DB2 does not support multiversion concurrency control, ie readers may be blocked by writers. DB2 does not support row level locking which is very important for heavily concurrent databases. PostgreSQL supports both transactions and row level locking. Only Oracle may compete with PostgreSQL in this area. NM > >
On Thu, 17 Feb 2000, Nemeth Miklos wrote:
> > And if this isn't too inflamatory a question, where does postgresql stand
> > in comparison to MySql and DB2? (both of which aren't free I believe).
> >
> MySQL does NOT support transaction, which is indispensable for a real
> DBMS used as the primary data storage system for reliable/consistent
> business transactions.
> However, MySQL is the fastest RDBMS ever seen, and perfect for data
> warehouses and DSS and EIS purposes, as well as for
> query databases for web sites.
MySQL is pretty free - you just canno redistribute it with commercial
applications.
MySQL is FAST! (MySQL is fast only on very simple SELECTs, but it is
more than enough for most Web projetcs.)
MySQL has very good fine-grained access control; you can GRANT almost
whatever you want to whomever (and REVOKE too) on a very selective basis:
GRANT select,insert ON my_data.table1 TO user1;
GRANT select,insert,update ON my_data.table2 TO user2;
GRANT alter,delete ON my_data.* TO user3;
MySQL has very good ALTER TABLE command.
MySQL has good support for Large Objects. I have a habit to store
and manipulate Web-images right in database using SELECT, INSERT, UPDATE.
Oleg.
----
Oleg Broytmann http://members.xoom.com/phd2/ phd2@earthling.net
Programmers don't die, they just GOSUB without RETURN.
Nemeth Miklos wrote: > PostgreSQL supports both transactions and row level locking. Only Oracle > may compete with PostgreSQL in this area. InterBase supports both transactions and row-level locking, with a multigenerational architecture similar to MVCC. -- Lamar Owen WGCR Internet Radio 1 Peter 4:11
At 10:10 AM 17-02-2000 +0100, Nemeth Miklos wrote: >> And if this isn't too inflamatory a question, where does postgresql stand >> in comparison to MySql and DB2? (both of which aren't free I believe). >> >MySQL does NOT support transaction, which is indispensable for a real >DBMS used as the primary data storage system for reliable/consistent >business transactions. >However, MySQL is the fastest RDBMS ever seen, and perfect for data >warehouses and DSS and EIS purposes, as well as for >query databases for web sites. MySQL is fast! As a data point for one of my webapps with MySQL- 30-50 hits/sec, with Postgres 7-8 hits/sec. Quite a significant difference. Heh one of my colleagues PHP + MySQL pages does 50+ hits/sec too. On just a workstation level machine... However, Postgres has triggers, transactions, and it's free and Open Source. MySQL is USD200 for commercial use and AFAIK not quite Open Source (at least not the latest versions, the older versions were made Open Source I think). About transactions, I find that they're not that useful in a typical web app, because 1) Many web apps are simple, and don't need transactions, or have simple work arounds. 2) And when you do need transactions, HTTP is not very state friendly, so unless you do something special your database level transaction is typically going to last only one page, so if your real life transaction spans across multiple pages, the database level transaction system isn't going to help much. Anyone have any ideas on how to get around that for Postgres? Coz if we have to do transactions at the application level then it might actually be better to just go MySQL, than to do transactions at both app and database level. Hmm any ideas on how to do MVCC at app level? ;). Session ID column and a committed boolean column? Or create a table for each session (ouch!), is that what temp tables are for? Do temp tables persist? Or is writing a 'session' server the way to do it? e.g. webserver->cgi/app server->session server->database server The session server is given a web session ID and SQL, and uses it to talk to the database. It also times out connections. Trouble is you don't know when users are leaving your site, so you could have tons of simultaneous database connections. Probably only doable or useful for niche applications- high concurrency limited user apps. Any better ideas? BTW: Somehow we seem to be going DB2 tho (dunno exactly why, but at least it's tons cheaper than Oracle, but infinitely more expensive than Postgres ;) ). Don't know much about DB2.. Cheerio, Link.
Hello Lincoln, On 18-Feb-00 05:40:51, you wrote: >About transactions, I find that they're not that useful in a typical web >app, because >1) Many web apps are simple, and don't need transactions, or have simple >work arounds. You mean that applications that require almost read only databases, or single table updates do not require transactions. You can't live without transactions outside that scenario unless you want to risk your applications to break due to database inconsistencies when many users are working with the application. >2) And when you do need transactions, HTTP is not very state friendly, so >unless you do something special your database level transaction is >typically going to last only one page, so if your real life transaction >spans across multiple pages, the database level transaction system isn't >going to help much. The way I see it transactions are meant to turn a set of queries virtually atomic. Anyway, transaction queries should be done one after the other. You should not leave a transaction open for an unrestricted period of time. If you need to hold locks on data for an unknown amount of time, you'd better find other solutions besides transactions. For instance if you want to hold on a ticket reservation for a client before he decides to purchase it, you should not use transactions to lock the reservation. Regards, Manuel Lemos Web Programming Components using PHP Classes. Look at: http://phpclasses.UpperDesign.com/?user=mlemos@acm.org -- E-mail: mlemos@acm.org URL: http://www.mlemos.e-na.net/ PGP key: http://www.mlemos.e-na.net/ManuelLemos.pgp --