Re: [GENERAL] The reasoning behind having several features outside
Jeff Davis wrote: Other people have answered, but I'd like to add: It makes it much faster to fix bugs and improve features in the projects outside of the source tree. If replication has a bug, you don't want to wait for the next point release, you want a fix *now*. PostgreSQL is a big project, and can't make new point releases every time a bug appears in a small subsystem. Replication is one subsystem not included in source tree. But PostgreSQL has other subsystems that are included such as plugins for procedural languages. So isn't the same risks involved with them? Tim ---(end of broadcast)--- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
[GENERAL] Reasoning behind process instead of thread based arch?
Hello! I have a couple of final ( I hope, for your sake ) questions regarding PostgreSQL. I understand PostgreSQL uses processes rather than threads. I found this statement in the archives: The developers agree that multiple processes provide more benefits (mostly in stability and robustness) than costs (more connection startup costs). The startup costs are easily overcome by using connection pooling. Please explain why it is more stable and robust? More from the above statement: Also, each query can only use one processor; a single query can't be executed in parallel across many CPUs. However, several queries running concurrently will be spread across the available CPUs. And it is because of the PostgreSQL process architecture that a query can't be executed by many CPU:s right? Although I wonder if this is the case in MySQL. It only says in their manual that each connection is a thread. Also, MySQL has a library for embedded aplications, the say: We also provide MySQL Server as an embedded multi-threaded library that you can link into your application to get a smaller, faster, easier-to-manage product. Do PostgreSQL offer anything similar? Thank you for your time. Tim ---(end of broadcast)--- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
Re: [GENERAL] Reasoning behind process instead of thread based
Two: If a single process in a multi-process application crashes, that process alone dies. The buffer is flushed, and all the other child processes continue happily along. In a multi-threaded environment, when one thread dies, they all die. So this means that if a single connection thread dies in MySQL, all connections die? Seems rather serious. I am doubtful that is how they have implemented it. ---(end of broadcast)--- TIP 2: you can get off all lists at once with the unregister command (send unregister YourEmailAddressHere to [EMAIL PROTECTED])
[GENERAL] PgSQL MVCC vs MySQL InnoDB
Hello Harrison Fisk from MySQL claims in this thread: http://forums.mysql.com/read.php?35,3981,4245#msg-4245 That there are no major differences between InnoDB and MVCC concurrency. Is this true? Thank you. Tim ---(end of broadcast)--- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
[GENERAL] The reasoning behind having several features outside of source?
Hello Why is it that PostgreSQL chooses to have features like replication, fulltext indexing and GIS maintained by others outside of the sourcetree? I appreciate any answers. Thank you. Tim ---(end of broadcast)--- TIP 6: Have you searched our list archives? http://archives.postgresql.org
Re: [GENERAL] Information about storge engine in PostgreSQL
I really appreciate these type of high-quality anwsers, thank you. Tim On 10/21/2004 10:27 AM, [EMAIL PROTECTED] wrote: Hello MySQL has information about several storage engines. MEMORY to handle temporary tables, InnoDB to handle transactions and which also can split its table data over several files/partitions. Splitting of storage is something which according to the following article, PostgreSQL does not support: For a long time the MySQL documentation was stating that foreign keys are mainly for documentation purposes and explained why you really didn't want them and why it was so much better that MySQL swallowed their syntax silently without any effect. Similarly dangerous opinions where documented about transactions and ACID features. Then the InnoDB table handler was added to MySQL and with the new features, namely transactions and referential integrity, the documented opinion about these features was changed. But since every other database had these features for long already, all that was left was now the capability of having different storage engines, and it became the new advantage feature to point out. Right now on their boiler plate is another buzzword compliant table handler, the NDB cluster storage engine. And while a lot of people are getting all excited about it, all I really see so far is yet another table handler that does not provide foreign keys, that does not integrate with the existing transaction systems ACID properties, and that has outrageous network and memory requirements. Especially worried am I about the fact that the responsibility for referential integrity, that was lifted from the developers shoulders with the InnoDB tables, is now dropped twice as heavy back into his laps. I don't think that Web developers who had problems getting integrity constraints implemented in the application before InnoDB will do this much better in a concurrent multimaster cluster environment. But I am sure enough PHB's who, free from every knowledge obstacles, fully believe in marketing speech will force their developers into that nightmare. None of all these advanced storage engines was developed by MySQL. They all got purchased and turned into table handlers. The multiple storage engine capability of MySQL is the technical base for stapling together those features, MySQL isn't able to build into the existing system and has to buy somewhere else. The PostgreSQL philosophy is a little different. That is why we have only one, tightly integrated and not very easy to replace storage engine. Jan -- #==# # It's easier to get forgiveness for being wrong than for being right. # # Let's break this rule - forgive me. # #== [EMAIL PROTECTED] # ---(end of broadcast)--- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
[GENERAL] Information about storge engine in PostgreSQL
Hello MySQL has information about several storage engines. MEMORY to handle temporary tables, InnoDB to handle transactions and which also can split its table data over several files/partitions. Splitting of storage is something which according to the following article, PostgreSQL does not support: http://www.devx.com/dbzone/Article/20743 But I cannot verify this due to lack of information. I haven't found any similar information about the storage engine used by PostgreSQL which I think is called Postgres. Do you know of any places where this information can be obtained? Thank you. ---(end of broadcast)--- TIP 4: Don't 'kill -9' the postmaster
[GENERAL] How to time several queries?
Hello I know it is possible to time isolated queries through the settting of the \timing option in psql. This makes PgSQL report the time it took to perform one operation. I would like to know how one can get a time summary of many operations, if it is at all possible. Thank you. Tim ---(end of broadcast)--- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
[GENERAL] Does PostgreSQL provide anything comparable with MySQL Cluster?
Hello Does PostgreSQL provide anything comparable with the functionality of MySQL Cluster? I appreciate all information. Thank you. Tim ---(end of broadcast)--- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
[GENERAL] Level of replication support?
Hello I am going to do a comparison betweem PgSQL and MySQL replication system. I hear there are some replication projects available for PgSQL. Which are still active and serious, because I hear that some are not active or incomplete? Will any of these projects be merged with PgSQL soon? I appreciate all information. Thank you. Tim ---(end of broadcast)--- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html
