Subtable type stucture in MySQL -


i know if possible have following database behaviour:

  1. create user table, primary key user_id
  2. data comes in external source: e.g. "user_id, timestamp, data"
  3. for each user in user table, create table store data entries pertinent user_id, , store incoming data correct user_id table
  4. when querying data entries specific user_id, return rows table.

i of course in 1 table "alldatalog" , search entries in alldatalog contain user_id, concern alldatalog table grows, searches take long.

you should not split tables that. want index on user_id column in data log table. searches become slower data size increases, strategy not mitigate that. make application more complex write, harder debug, , quite slow down.

you should consider unpacking data blob additional columns , tables appropriate in order take advantage of relational nature of database.

how many rows expect table hold on time? thousands? millions? billions? @ rate expect rows added?


Comments

Post a Comment

Popular posts from this blog

SPSS keyboard combination alters encoding -

my question not have programming practical issue on spss. accident keyword combination cannot remember because did not intend press changed encoding in spss , text in data in different language english shown small boxes. nevertheless, when kind of analysis performed different language text shown in output. does know reason? tried change encoding did not produce result. first, @ edit > options , see whether setting unicode or locale. might fix it. if have text in multiple languages, want unicode. otherwise, may have specific locale set wrong. can change set locale, need know locale want use.
Read more

Add new record to the table by click on the button in Microsoft Access -

in ms access form want implement separate button, adds new record table. in order added button , attached button event: private sub btnaddrec_click() refresh codecontextobject on error resume next docmd.gotorecord , , acnewrec if err.number <> 0 btnaddrec.enabled = false end if end end sub everything ok when open window , click btnaddrec button, problem when first of perform navigation through existed records , after click on button. got runtime error: 2105: «you can't go specified record. may @ end of recordset» . how solve issue, need have ability add new record on click on specific button, no matter, have walked or not walked through records before. thanks. i created simple form field call description (and autonumber) , created button code follows click event. filled number of records , navigated through them, clicked addnewrec button. form navigated new record without issues. able click addnewrec button directly after
Read more

javascript - jQuery .height() return 0 when visible but non-0 when hidden -

i have problem here right opposite others: in jquery cannot height of element when it's visible, when hidden. have html code: <div id="filtering-filter-holder"> <div id="filtering-filter-holder-inner"></div> </div> basic css it: #filtering-filter-holder { display: none; position: absolute; width: 420px; min-height: 100px; padding: 5px 5px 5px 5px; background-color: #ffffff; border: 1px solid #164372; } and finally, js in document.ready(): $('div.filtering-filter-headline').mouseenter(function() { var el = $(this).parent().find('div.filtering-filter-content'); if ($('div#filtering-filter-holder').is(':visible')) { $('div#filtering-filter-holder-inner').stop(true, true).fadeout(300, function() { $('div#filtering-filter-holder-inner').html($(el).html()); var height = $('div#filtering-filter-holder-inner&#
Read more