Is there a performance difference between using a BETWEEN clause or using <= AND >= comparisons?
i.e. these two queries:
SELECT *
FROM table
Actually it depends on your DBMS engine.
Some database management systems will compute twice your expression (once for each comparison), and only once when you use BETWEEN
.
Actually if the expression can have a non-deterministic result BETWEEN
will have a different behaviour, compare the following in SQLite:
WHERE RANDOM() BETWEEN x AND y -- one random value generated
WHERE RANDOM() >= x AND RANDOM() <= y -- two distinct random values generated
This can be very time consuming if your expression is (for example) a subquery.
It should be the same.
Good database engine will generate same plan for that expression.
When in doubt (for Oracle anyway), run an explain plan and you'll see what the optimizer wants to do. This would apply to most questions about "is there a performance difference between ...". Of course there are a lot of other tools also, but explain plan is a good start.
run1 "X>=Y AND X<=Z"
run2 "X BETWEEN Y AND Z"
I get one Plan hash value
when I run explain plan twice.
But Tom's runStats_pkg get diffent result:
Run1 ran in 1 cpu hsecs
Run2 ran in 1 cpu hsecs
run 1 ran in 100% of the time
Name Run1 Run2 Diff
STAT...recursive calls 12 13 1
STAT...CPU used by this sessio 2 3 1
STAT...physical read total IO 0 1 1
STAT...consistent gets 18 19 1
...
...
LATCH.row cache objects 44,375 1,121 -43,254
LATCH.cache buffers chains 68,814 1,397 -67,417
STAT...logical read bytes from 655,360 573,440 -81,920
STAT...session uga memory max 123,512 0 -123,512
STAT...session pga memory 262,144 65,536 -196,608
STAT...session pga memory max 262,144 65,536 -196,608
STAT...session uga memory -327,440 65,488 392,928
Run1 latches total versus runs -- difference and pct
Run1 Run2 Diff Pct
203,927 28,673 -175,254 711.22%
You better check your execution plans because there can be some weird edge cases where BETWEEN
can have a different execution plan from the standard >= and <= combination.
https://blog.pythian.com/oracle-can-between-and-greater-than-or-equal-to-and-less-than-or-equal-to-differ/
Caveat emptor obviously. But since execution plans can change over time and I really do not have an appetite to test such things, I rather not use BETWEEN at all.
Sometimes less choice is better.
There is no difference.
Note that BETWEEN
is always inclusive and sensitive to the order of the arguments.
BETWEEN '2010' AND '2005'
will never be TRUE
.