Contention in a parallel app or did MySQL lose its marbles?
I have a program which read rows from one table (new_data) and attempts to find a matching record in another table, called master_table. Upon determining a that we have seen a record from this client (in new_data) before, based upon some exact matching and probability matching logic, we insert the new record into the master_table. The typical size of the input table (new_data) is 40-65 million rows). So the master_table will grow substantially over time, and the speed of processing an inbound table against the master_table will fall off too. We expect that, anyway. We've have partitioned the perl program with record keys that it should process, such that we can run 2 or more copies of the process and get through the new_data table(s) quickly without stepping on each others toes. The following is the configuration: 2way 2.8Ghz Intel, RHAS 3.0 (Hyper-threaded) 6Gb Memory 14x72 Gb 10k RPM drives MySQL 4.1.1-alpha-standard-log (using all MyISAM tables) Perl v5.8.0 built for i386-linux-thread-multi DBI 1.42 my.cnf: [mysqld] datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock key_buffer_size=3G table_cache=1024 # Save our bodies from carpel tunnel lower_case_table_names = 1 # Log slow queries for inspection later. long_query_time=2 log-long-format log-slow-queries = /home/jgd/SlowQuery.log # End slow query log params [mysql.server] user=mysql basedir=/var/lib [safe_mysqld] err-log=/var/log/mysqld.log pid-file=/var/run/mysqld/mysqld.pid We were processing a test set of 7.5 million rows in a new_data table and hit between 339 and 505 rows per second. However, in the logs, I noticed some (potentially) concerning messages. Even though all rows were processed and accounted for, I am at a loss to explain the errors, this one in particular: -- [Fri May 28 03:30:37 2004] mp_thread4.pl: DBD::mysql::st execute failed: Got error 127 from storage engine at cmp.pl line 4555. -- Any pointers? Or did I leave anything out in this overly written message? TIA. -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: Getting distinct counts (solved)
...blind as a bat, it was right in front of me in basic SQL . Thank you kindly. -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: Creating Users and Passwords
hmmmif you are on the same machine, does it work if you do not specify the '-h localhost'? -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: Creating Users and Passwords
What is the version of your mysql client? If it is pre 4.1 then it is likely being bitten by the password length change from 4.0.xx to 4.1 from 16bytes to 41bytes. You'll need to read the note on passwords in the 4.1 docs. Hope this helps. -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Getting distinct counts
I am using MySQL 4.0.18 and trying to generate a list of the number of row in a table with the same last name, by last name. Is there any way to do this without creating another table? Here is what I am trying: mysql> select count(distinct last_name) as "LnameCnt", last_name from table_ABC group by last_name; ...such that I could get this: LnameCnt last_name -- 10 Connor 255Jones 2 Puttinger Any ideas? TIA, tony -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: client and server question
In a message dated 2/15/2004 4:39:00 PM Eastern Standard Time, [EMAIL PROTECTED] writes: I've got an iBook running gentoo and MySQL version 4.0.17 and it's on the same router with my desktop running gentoo and MySQL version 4.0.17. I would simply like to use the iBook as a mysql client and have it connect to the mysql server running on my desktop. What is the simplest way to accomplish this? I am not familiar with 'gentoo' but connecting a mysql client to a server is pretty straigh-forward: at the command prompt on the client: mysql -h DB-server-hostname-or-IP -u YourMySQL-username -p YourMySQL-user-name password DB-name >From an application standpoint, that depends on the tool being used, but there are several methods, a C/C++ API, ODBC drivers, a JDBC driver, Perl'd infamous DBI engine, PHP, etc. Not trying to duck the question, but it really depends on the amount of data, size of the database, your programming skillset,, whether you are using off-the-shelf products, etc. Many paths, much documentation on the mysql.com site. I'd start there. HTH. /t
Re: best-practices backups
In a message dated 2/11/2004 2:26:09 PM Eastern Standard Time, [EMAIL PROTECTED] writes: I read this over and over.. I am curious why replication is such high finance?? I run it here. The Production system is a high finance machine and the replicated box is a old clunker basically.. It doesn't take much for the stuff to be replicated over.. The high dollar has queries, this and that. The replicated machine is just simply keeping up with the changes.. That's it. You could do that with just about any decent machine.. I would think.. sure, there is going to be the few that load and change data constantly.. But I still think that would be ok.. (have to test it). Do you guys agree? Hmmm...not in all cases. While I'll agree that this would be a cost-effective method for many MySQL installations, I use MySQL for in a data warehousing environment which typically has few, but extremely large bulk updates. We are in the multi-TB range, so this would not work for us.
Re: best-practices backups
In a message dated 2/11/2004 4:44:00 PM Eastern Standard Time, [EMAIL PROTECTED] writes: Hi, I do just this at the moment - I have a cron job that runs MySQL dump, gzips the output, and will then ftp the important files to a machine that get's backed-up to a tape drive. I also time the dump, and it currently takes just over 3 minutes which is quite acceptable for what I'm doing. I'm thinking about piping the output of mysqldump straight through gzip and then ftp'd away to ease the disk access too, but that maybe later. I would still like a best-practices guide though, so that if everything does go wrong I'm sure that I've got everything I need to reconstruct the system as swiftly as possible. I've done some dry runs, but still feel that this isn't the same as learning from that gleaned by others that may have actually been faced with disaster in the past! Thanks, Mike Mike, This is a great topic of interest to me, as I am rolling out MySQL throughout our enterprise and naturally, the MS SysAdmin are not comfortable doing backups on a Linux box--so I move the dumps to their backup server. Have you tried to do all of that in one step using SSH? For example, I often transfer big datafiles using the following command: tar cf - BigUncompressedDataFile | ssh -C [EMAIL PROTECTED] tar xf - This effectively compresses the data on the fly, without creating a temporary tar file; pipes it to the remote host over SSH ( I use -C for SSH compression in case any more could be squeezed out) and then uncompresses the file on the remote host. Seems to me that your process makes perfect sense, I am just lazy and would want it one in one command in my cron job. However, that's just what I use to transfer files to a place I want to work on them, in an uncompressed format on the remote host...obviously not what you'd do for backups. I'll mess with trying this with secure copy (SCP) to replace the SSH portion above. Just thinking out loud. A Backup/Restore Best Practices Guide would be very valuable to everyone I should think. Happy to help develop/host one if anyone wants to pitch in ideas. /T
Q: Load Infile (Fixed Length)???
Hello. I've been using 'load data infile...' to build a data warehouse and it seems to be extremely efficient. However, I receive very large, fixed delimited file and (so far) have to parse them with a little Perl code. It's not a terrible situation, but a step I'd like to eliminate if I could use 'load data infile...' from a known fixed file format. Is this possible? Thanks in advance. Tony
Merge Tables not working...
Hello, I've posted this before, but did not get a fix or find out what I am not doing coreectly. I've established several merge tables. 3 out of the 5 of my merge tables work fine...but when I try to access (e.g. describe or query) the other two, I get the following error: mysql> describe hospchar; ERROR 1016: Can't open file: 'employee.MRG'. (errno: 143) mysql> I am running MySQL 4.0.15-max-nt on Windows 2000 Professional. Any ideas? Thanks in advance. Tony -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: moving databases
In a message dated 10/29/03 4:18:28 AM Eastern Standard Time, [EMAIL PROTECTED] writes: > Ok, I've set my root password and have found (by creating a db) that > the databases are stored (Mac OSX Server 10.3) in /private/var/mysql. > > I have my old system on a separate hard disk; however, mysql is not > functioning there, but I do have my databases there. Can I copy these > database to their new home? How will MySQL recognize them? (What is > the best way in my situation to accomplish this move? (Again, MySQL is > not available to 'run' where they are.) I have not used Mac OSX, but I had a similar situation migrating my company to Linux from Windows2000 in our datacenter. I just moved the files over as I recall. You need to create a sub-directory under the DataDir (looks like under /private/var/mysql in your case) and I restarted MySQL. NOTE: All my tables were MyISAM. This may not work with InnoDB tables. HTH -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Q: MERGE table limitations
Does anyone know of any limitations on the number of underlying tables in a MERGE table? Seems to be a topic of scant coverage in the books and online docs. ANY help or ideas would be appreciated. /Tony -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
MERGE tables error
I've created several merge tables from the command prompt. All seems well, the .frm and .MRG files are created. The contents of the .MRG files are accurate. I flushed the tables (even restarted MySQL). I can see the newly created merge tables, but when I try to run a DESCRIBE or a SELECT COUNT(*) to verify the records counts, I get the following error message: ERROR 1016: Can't open file: 'new_master.MRG'. (errno: 143) All table structures are identical. Am I missing a basic error numbers page in the online docs? I've found a few, but nothing comprehensive, like a page where I can enter an error number and find the detailed message, probable cause, recommdned action, etc. The only thing that I have been able to find is: http://www.mysql.com/doc/en/Error-returns.html which essentially confirms that an error 1016 is a problem opening a file. I am using MySQL version 3.23.56-nt on Windows2000. Any help, links or guidance would be greatly appreciated. /Tony -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: ODBC Encryption?
What you've seen is what you get. None. Try tunneling through SSH. Try this link to learn more: http://www.cs.kuleuven.ac.be/system/security/ssh/tunnel.shtml -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: msaccess frontend
We use MS Access with ODBC links to MySQL, but prefer a commercial product called MyManager. It cost about $199.00 US. for the professional version. looks and works much like MS Access. There are several on the market, we chose this one as the best for our purposes. Here's the link: http://ems-hitech.com/mymanager/ -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: Parallel Processing
In a message dated 10/16/03 9:27:04 AM Eastern Daylight Time, [EMAIL PROTECTED] writes: > This is down to the OS. As MySQL is multy threaded its all down to SMP > support. > with all due respect, I don't think that is 100% true. Although certainly the underlying OS kernel must support multi-processors and discrete processor selection functionality, I am looking for user-based control of query execution. That would have to come from the DB package. Oracle has such functionality (at least on Unix-based versions) that I've used recently, including the ability to dynamically allocate more processors to a running query. We do this all the time to complete a task of higher priority than others. Certainly with Oracle one pays dearly for such software. I am just wondering what options are available in MySQL (if any). For example, I want to enable one user to perform read-only queries using the full machine resources. Other times, I'd like to restrict the queries from a specific user or group to processor 0 while the other 3 (or more) are dedicated to handling higher priority tasks. Its likely that such features would bloat MySQL ... and I'd never want that, not even a fan of the sotred-procs... just making sure I am not missing something in the docs or from some of the wizardry out there. :-) -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Parallel Processing
I've been reading the online docs and asking around about MySQL's ability to perform parallel processing. It does not appear to support such functionality. Maybe this is intentional, or I missed something in the manual. I have a 4 way Intel server that I'd like to be able to contain certain user's queries to certain processors. Does anyone know of a method/tricks/techniques to achieve this? RedHat Linux 9 MySQL 3.23.54 Thanks in advance, Tony -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: copy database
In a message dated 9/30/03 3:13:59 PM Eastern Daylight Time, [EMAIL PROTECTED] writes: > What if you have InnoDB tables? I don't. ;-) But I'd certainly like to know other strategies. -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: copy database
In a message dated 9/30/03 1:33:07 PM Eastern Daylight Time, [EMAIL PROTECTED] writes: > HI List, > > > > Using version 4.0.15 > > > > I'm trying to copy a database. Copy db1 to (new) db2. > > > > So I created db2. > > > > And then tried the following and got the subsequent errors. > > > > # mysqldump --add-drop-table db1 | mysql db2 > > > > ERROR 1064 at line 399: You have an error in your SQL syntax near > 'count(count), > >KEY dataID(dataID) > > ) TYPE=MyISAM' at line 15 Why not just copy the [MySQL-data-dir]\DB1 to [MySQL-data-dir]\DB2? That works for me, even when I am moving/copying a database from a Windows machine to a Linux machine. Hope this helps. Tony -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: DataDir question
...after finding a log in the directory that I was trying to use for my new DataDir, I've discovered my problem (and, surprise, it makes sense). The MySQL database table must also be in place in the directory, I suppose in order to keep track of the other databases and tables, etc. Cheer. -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: DataDir question
In a message dated 9/24/03 12:34:34 PM Eastern Daylight Time, [EMAIL PROTECTED] writes: > Have you tried using the blackslash? `\` instead of the forward slash `/`? Same results. The manual states that even on Windows that the '/' should be used as the '\' is MySQL's escape char. Optionally, you can '\\' but all three methods produce the same result. :-/ -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
DataDir question
I am using a portable drive with a few tables on it that I copied from a MySQL server. My intent is to be able to transport the portable drive home (with the large DB) and plug it into my Windows server to continue working. To do this, I need to change the datadir to the portable drive (in my case it's the L: drive). I've tried putting an entry in my c:\winnt\my.ini file under the [mysqld] line as follows: [mysqld] datadir=L:/dbdir ...but it refuses to startup. I have to admit that am more comfortable in Linux, so I could be missing the error or logfile. The only thing in the Event Log is: The MySql service terminated unexpectedly. It has done this 1 time(s). The following corrective action will be taken in 0 milliseconds: No action. I've also removed the my.ini file and specified --datadir L:/dbdir in the services window and that seems to start the server ok, but I can't see the database tables. Anyone know what I am doning wrong? -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Q: Moving a database
Has anyone ever had to move a database from one machine to another? I tried to just copy all the files from /var/lib/mysql/db1 to another machine into /var/lib/mysql/db2. Although I can see the tables using SHOW TABLES, I get an error 13 trying to access or repair them. Is it possible to move a database this way? -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: MySQL/Cron problem
Hmmm, have you tried putting is a folling mysqladmin flush-threads command? -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: MySQL ssl Q
In a message dated 9/15/03 3:05:09 PM Eastern Daylight Time, [EMAIL PROTECTED] writes: > Hey, > > Does anyone have any suggestions? Is this the correct list to post MySQL > ssl questions? I didn't get any responses so far. Thanks. > > Sherrill Are you orunning the monitor from the same machine that you tested with DBI? If not, it may be that you need to grant access to the IP address (and user) from the monitor machine. Just using the same userID is not enough usually as you can restrict by IP address. Just a thought. -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: Joining tables from two different databases
In a message dated 9/15/03 9:50:22 AM Eastern Daylight Time, [EMAIL PROTECTED] writes: > Jeff McKeon wrote: > > > Is it possible to relate a record in one database to a record in another > > and do queries that pull from both databases? Programmatically yes. Using referential integrity (foreign keys), I doubt it. :-( /tony -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Q: 3rd party ADO access to Mysql?
Has anyone ever used a non-ODBC, 3rd party ADO connector to MySQL? Any suggestions would be greatly appreciated. My client does not wish to use ODBC. /tony -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: a few questions regarding MySQL rights
In a message dated 9/13/03 8:40:08 AM Eastern Daylight Time, [EMAIL PROTECTED] writes: > 1) can I create groups, add users and assign privileges to the group? Yup. > 2) since this system is going over a VPN the data should be encrypt using > 3DES. If a authorized user needs access to the data who is not in the VPN > this information would be traveling in a clear text format (please correct > meif I'm wrong) but is there a way to encrypt the data? For starters, I'd recommend always using SSH (whether VPNing or not) to encrypt the pipe (puTTY.exe is a great, free Windows-based terminal emulator for that, or Cygwin). It also depends on how your users are connecting (VPNers and other) and are you planning on using ODBC? If so, check out the net on redirecting ODBC requests through SSH. That way the pipe is encrypted, so whether the data is or not is less (but still) important. The config is something like this: ssh -L 80:192.168.0.254:80 -l root -T 192.168.0.254 (You'll need the root password to the DB machine in this case) Check out: http://archives.postgresql.org/pgsql-odbc/2001-09/msg00040.php for more info. How will you be maintaining the DB? Through scripts? If so, SSH and ban Telnet. If you plan to use a GUI, you might check out www.ems-hitech.com/mymanager which provides a method for using SSL (its about $135.00 US). HTH, Tony -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: Error while altering a table
...just a shot in the dark, but isn't 'description' a reserved word? If so, um, maybe a bug/inconsistency between table types. If not, ramble on. -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: Distributing a DB
In a message dated 9/9/03 7:53:59 PM Eastern Daylight Time, [EMAIL PROTECTED] writes: > By "partitioning", you mean having one table divided across N > partitions? Yes, I do. > > Such a feat isn't directly possible with MySQL, however you can create N > tables instead of 1, and use a table of Type=RAID on the master to > "unify" them for purposes of queries that need to access data from many > partitions. I've read about using symbolic links, but only for using multiple data directories, not splitting a file (not to mention, across more than one node). Admittedly, I am not a Linux/*nix guru, just adventurous and doing research soliciting opinions/ideas before I dive in. Since MySQL doesn't directly support this, any ideas on doing it at the OS level to 'trick' MySQL into believing its all in a single directory as a single table? It's looking more like I may have to build a DBsmart API to select the partition/machine containing the data I need. I recall a group of sharpsters at Temple U. did something similar to that. /t -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Re: Distributing a DB
In a message dated 9/9/03 4:52:53 PM Eastern Daylight Time, [EMAIL PROTECTED] writes: > If you're accessing your db through JDBC, an idea that I've been following is > the c-jdbc project... Very nice, but we will be using LAMP (Perl and PHP). :-/ > > http://c-jdbc.objectweb.org/ > > it's software raid clustering for databases... it's still in beta, but it > looks very promising for easy clustering. Combined w/ MySQL's master/slave > setup, it could be a very robust solution... Interestingly comparable... > it basically creates a virtual db out of the connected machines, to the > point where you can have different tables on different boxes. Sounds very similar, but I need true partitioning, not separate tables. > It's at least worth looking into Sure is, thanks. -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Distributing a DB
Hi, We are trying to find a way to distribute a large MySQL database across several systems, each configured as a master to a slave. At this point we are tossing architectural ideas around and here is where we are right now: Primary (Master) MySQL DB | +++---+ | | | | partitionA-G partitionH-M partitionN-SpartitionT-Z | | | | | | | | <<<(MySQL Replication)>> | | | | VV VV slaveA-GslaveH-M slaveN-S slaveT-Z (slaves) Machines - Primary DB dual 2.2+ Ghz/1Gb RAM and 250Gb of RAID 1 storage, dual Gb eth <<<(Gb Ethernet Switch)>>> PartitionA-G dual 2.2+ Ghz/2Gb RAM and 2Tb of RAID 5 storage, dual Gb eth PartitionH-M dual 2.2+ Ghz/2Gb RAM and 2Tb of RAID 5 storage, dual Gb eth PartitionN-S dual 2.2+ Ghz/2Gb RAM and 2Tb of RAID 5 storage, dual Gb eth PartitionT-Z dual 2.2+ Ghz/2Gb RAM and 2Tb of RAID 5 storage, dual Gb eth <<<(Gb Ethernet Switch)>>> SlaveA-G dual 2.2+ Ghz/2Gb RAM and 2Tb of RAID 5 storage, dual Gb eth SlaveH-M dual 2.2+ Ghz/2Gb RAM and 2Tb of RAID 5 storage, dual Gb eth SlaveN-S dual 2.2+ Ghz/2Gb RAM and 2Tb of RAID 5 storage, dual Gb eth SlaveT-Z dual 2.2+ Ghz/2Gb RAM and 2Tb of RAID 5 storage, dual Gb eth The idea is that users would typically connect to the PartitionA-Z for normal read access. Overflow queries would connect to the SlaveA-Z. Update processes would connect to the Primary DB machine. For what its worth, we will be running RH 9.0, MySQL 4.0??? (depending on features we need to accomplish this); no two-phase commit transactional support required, no stored procs. I am not certain about how to split the database across multiple machines (or is can be done). we are also toying with the idea of using a hardware load balancer as a fabric of sorts to route traffic and possibly bi-directional replication . Has anyone ever tried this? Have any thoughts? Thanks in advance. Tony -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Temporary Tables
I am trying to establish temporary tables that are accessible via MyODBC. I can create the table with data in it and query it from the MySQL command line, but it never shows up through MyODBC. Is there something magical about temporary (memory-based) tables that prevents this? I am running MySQL 4 on RedHat 9 with the latest MyODBC. The create syntax works as advertised: create temporary table X select * from Y where Z = 'abc'; Incidentally, MyODBC works fine with disk-based tables. I just set up an ODBC DSN and can access all the tables via Excel, MS Word, MS Access, etc. except the temporary tables. TIA. -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Temporary Tables
I am trying to establish temporary tables that are accessible via MyODBC. I can create the table with data in it and query it from the MySQL command line, but it never shows up through MyODBC. Is there something magical about temporary (memory-based) tables that prevents this? I am running MySQL 4 on RedHat 9 with the latest MyODBC. The create syntax works as advertised: create temporary table X select * from Y where Z = 'abc'; Incidentally, MyODBC works fine with disk-based tables. I just set up an ODBC DSN and can access all the tables via Excel, MS Word, MS Access, etc. except the temporary tables. TIA. -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Q: Delete subselect
I know that MySQL 3.23.nnn did not support a delete subselect, just wondering what the best/most efficient way to do the following is: delete from table_a where table_a.column_1 in ( select column_1 from table_b); Assuming that column_1 is the same data type and size in both table_a and table_b. Any help would be greatly appreciated. Regards, Tony
UnixODBC Perf Question
Has anyone had much luck with UnixODBC on RedHat Linux. I've recently moved a 100 Gb MySQL database from Win2000 Server to a RedHat 9 server and installed UnixODBC to access it. It appears that the performance is dramatically slower using the same application, pointed to the RedHat server. The performance of command line queries works as expected on the Linux box. I have to use ODBC to access the data (unless anyone knows of a SAS Access for MySQL module in development--hint, hint, nudge, nudge). TIA. -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
