Reusing deleted variable-size record space
Hello I have a database with variable-size fields, some of them may be modified/deleted during the usage and administration, so my doubt is: how can I compact the records to remove those blank spaces and save space, lets say "defragment" the database file so data is continuous and contiguous? This task should be performed just once or twice a month, so no matter if it could take a while. Is there an internal function to do that? I could copy existing records to a new table, delete all the original ones and then insert them back and drop the second table but don't like it too much. Thanks for any suggestion -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Selecting just 'N' first rows
Hello How can I send a query that retrieves only the first 'N' rows that match a condition? As far as I know you must call mysql_fetch_row() until the last row has been processed or the resources allocated won't be free. Am creating a program in PHP that should retrieve only 'N' records each time a query is sent, so I I'm thinking on using mysql_free_result(), but, is it safe to free the results even if there are more records remaining that match the query conditions? I need to know how secure could be to read only the first records and free the resources, or if there is another way to do the same thing. Thanks, Miguel -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Lengtht of TEXT data types
Hello list I have doubt on TEXT data types... Checking my notes I see these ones: TINYTEXT/TINYBLOB (2^8) 255 chars TEXT/BLOB (2^16) 64K chars MEDIUMTEXT/MEDIUMBLOB (2^24) 16M chars LONGTEXT/LONGBLOB (2^32) chars Well, my doubt consist on this... are these FIXED lengths for the text fields or they have variable length that may grow up to that as maximum? I require to store messages of variable length from 1 to 1024 characters, so TINYTEXT is too short and TEXT is too large, so I want to know if it they have variable length analog to the VARCHAR type and the client program only ensures the messages to have 1024 length... Thanks for your help -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
Joining *3* tables
Hello list I have a large database of contacts, but since not all fields are used I decided to separate all information in 3 tables to save space like this: DB_ADDRESS id int address char(128) ... three columns more ... DB_COMPANY id int company char(64) DB_LISTS id int list char(16) Not all addresses have necesarily a company name, so it is separate in a table DB_COMPANY. Some other addresses are clasified in lists by category and they are grouped in DB_LISTS table. If I want a report with address and company name pairs I use: select address,company from DB_ADDRESS left join DB_COMPANY on DB_ADDRESS.id=DB_COMPANY.id where DB_COMPANY.id is not null; If I want a report of address belonging to a certain category: select address,list from DB_ADDRESS left join DB_LISTS on DB_ADDRESS.id=DB_LISTS.id where DB_LISTS.id is not null and DB_LISTS.list="providers"; BUT... If I want to generate a report with address, company and list (category) how can I join the three tables with a single query? or should I first generate a temporal table with the result of the first join and then a second one joining the third table? Thanks for your comments -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL PROTECTED]
