Question

I have a situation where I need to use a huge number for the limit. For example,

"select * from a table limit 15824293949,1";

this is….really really slow. Sometimes my home mysql server just dies.

is it possible to make it faster?

sorry the number was 15824293949, not 38975901200

Added:

**Table 'photos' (Sample)**

Photos
img_id img_filename
1       a.jpg
2       b.jpg   
3       c.jpg
4       d.jpg 
5       e.jpg
and so on

select cp1.img_id,cp2.img_id from photos as cp1 cross join photos as cp2 limit ?,1

How I get 15824293949?

I have 177901 rows in my photo table. I can get the total # of possible combinations by using

(total # of rows * total # of rows ) – total # of rows)/2

Answer 1

Try limiting the query with a WHERE clause on a column with an index on it. E.g.:

SELECT * FROM table WHERE id >= 38975901200 LIMIT 1

Update: I think perhaps you don’t even need the database? You can find the nth combination of two images by calculating something like 15824293949 / 177901 and 15824293949 % 177901. I suppose you could write a query:

SELECT (15824293949 / 177901) AS img_id1, (15824293949 MOD 177901) AS img_id2

If you’re trying to get them from the natural order that they’re in the database (and it doesn’t happen to be their img_id) then you might have some trouble. Does it matter? It’s not clear what you’re trying to do here.