Re: generic question re. image blobs in dbs
Well, if you have other varchar fields in your table, then it probably wouldn't have any impact on performance. But since BLOBS and TEXT are considered varchar, the table no longer is a fixed width. It is my understanding that MySQL can locate specific records faster (even with indexes) in tables with fixed widths (i.e., no variable-length columns). - Original Message - From: "WCBaker" <[EMAIL PROTECTED]> To: "MySQL" <[EMAIL PROTECTED]> Sent: Friday, February 23, 2001 11:07 AM Subject: generic question re. image blobs in dbs > Hi! > > There is a consensus that blobs containing image files like .jpgs, .gifs, > etc. might better be stored just as links in the database, with the actual > files in a directory pointed to by the database links. Forgive my > ignorance, but can someone explain a few of the more obvious reasons why > this makes a difference? For example, if I avoid SELECT * when referring > to a table with blobs it seems to be pretty fast. . .So I'd only refer > to the heavyweight column when absolutely necessary. Does it take a lot > longer to pull out the blob than it would to load the file contents into a > browser? > > Thanks for any information you can impart! > > Cheers! > > -Warren > > > - > Before posting, please check: >http://www.mysql.com/manual.php (the manual) >http://lists.mysql.com/ (the list archive) > > To request this thread, e-mail <[EMAIL PROTECTED]> > To unsubscribe, e-mail <[EMAIL PROTECTED]> > Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php > - Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
Re: generic question re. image blobs in dbs
You are absolutely correct But in some situations, using BLOBs inside the database is more convinient. Consider for the example the case where you might want to migrate the data to another location. If some of the data are existing as external files, this might be a very difficult process. And allowing an external OS to manage some of the data might result in dangling links if some one accidently deletes the external file. About enhancing the performance of the queries, you can avoid using SELECT * and select only the fields that you are interested in and only SELCT the bolb objects when you need them Hesham Farouk Anan Computer Science Department Old Dominion University Norfolk, VA 23529 - Original Message - From: "WCBaker" <[EMAIL PROTECTED]> To: "MySQL" <[EMAIL PROTECTED]> Sent: Friday, February 23, 2001 12:07 PM Subject: generic question re. image blobs in dbs > Hi! > > There is a consensus that blobs containing image files like .jpgs, .gifs, > etc. might better be stored just as links in the database, with the actual > files in a directory pointed to by the database links. Forgive my > ignorance, but can someone explain a few of the more obvious reasons why > this makes a difference? For example, if I avoid SELECT * when referring > to a table with blobs it seems to be pretty fast. . .So I'd only refer > to the heavyweight column when absolutely necessary. Does it take a lot > longer to pull out the blob than it would to load the file contents into a > browser? > > Thanks for any information you can impart! > > Cheers! > > -Warren > > > - > Before posting, please check: >http://www.mysql.com/manual.php (the manual) >http://lists.mysql.com/ (the list archive) > > To request this thread, e-mail <[EMAIL PROTECTED]> > To unsubscribe, e-mail <[EMAIL PROTECTED]> > Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php > > - Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
generic question re. image blobs in dbs
Hi! There is a consensus that blobs containing image files like .jpgs, .gifs, etc. might better be stored just as links in the database, with the actual files in a directory pointed to by the database links. Forgive my ignorance, but can someone explain a few of the more obvious reasons why this makes a difference? For example, if I avoid SELECT * when referring to a table with blobs it seems to be pretty fast. . .So I'd only refer to the heavyweight column when absolutely necessary. Does it take a lot longer to pull out the blob than it would to load the file contents into a browser? Thanks for any information you can impart! Cheers! -Warren - Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
