Until this change we were stripping prefix from object key on satellite side. Because of that we were transferring over network unnecessary data
from DB. This change adjusts iterator SQL queries to use SUBSTRING to
remove prefix on DB side and avoid sending it to satellite.
Benchmark against 'main':
unfortunately "time/op" is very unstable while doing local bench in this
case and sometimes there is no difference in time and sometimes its up to 18%. I never saw results when old solution is faster then new one. Results for "alloc/op" and "allocs/op" are rather consistent.
name old time/op new time/op delta
NonRecursiveListing/Cockroach/listing_no_prefix-8 1.98ms ± 6% 2.05ms ±23% ~ (p=1.000 n=9+10)
NonRecursiveListing/Cockroach/listing_with_prefix-8 3.97ms ± 8% 3.42ms ±20% -13.86% (p=0.005 n=10+10)
NonRecursiveListing/Cockroach/listing_only_prefix-8 8.42ms ±16% 7.58ms ± 5% -9.91% (p=0.002 n=10+10)
name old alloc/op new alloc/op delta
NonRecursiveListing/Cockroach/listing_no_prefix-8 16.7kB ± 0% 16.9kB ± 0% +1.16% (p=0.000 n=10+10)
NonRecursiveListing/Cockroach/listing_with_prefix-8 27.3kB ± 0% 28.2kB ± 0% +3.31% (p=0.000 n=10+10)
NonRecursiveListing/Cockroach/listing_only_prefix-8 60.0kB ± 0% 62.4kB ± 0% +3.93% (p=0.000 n=10+8)
name old allocs/op new allocs/op delta
NonRecursiveListing/Cockroach/listing_no_prefix-8 312 ± 0% 315 ± 0% +0.96% (p=0.000 n=10+10)
NonRecursiveListing/Cockroach/listing_with_prefix-8 526 ± 0% 541 ± 0% +2.85% (p=0.000 n=10+10)
NonRecursiveListing/Cockroach/listing_only_prefix-8 1.16k ± 0% 1.23k ± 0% +5.24% (p=0.000 n=10+10)
Change-Id: I23e501494ededafb2dd5ea903e8e4e313b42e956
db1409eea6