if had view (or table) contained millions of rows , executed these 2 queries different sessions, 1 query adversely affected another? (please note no dml going on)
e.g. select * t1 sex = 'm'; (returns 20 columns , 10,000 rows) select sex t1 rownum < 2;
what if had multiple sessions executing query 1? equally slow until 1 of them had been cached (provided large enough)?
i experiencing degraded performance when executing similar queries in load balancing test quicker queries, when executed separately (even when result hasn't been cached) getting 'normal' response times.
if tables not being modified , queries using base tables, surprising if these 2 queries interfering each other. in particular, second query:
select sex t1 rownum < 2; should fetching 1 row , going fast.
the first can take advantage of index on t1(sex).
if t1 view, oracle has processing view. twice, once each query. if view complex, put load on server , slow down.
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