use dedicated db connection for read and write in logs db

[libotony]

Description

Ticket https://github.com/vechain/protocol-board-repo/issues/1004

The benchmark result shows that the PR has the same performance as the previous change.

benchstat target1.txt pr1.txt
goos: darwin
goarch: arm64
pkg: github.com/vechain/thor/v2/logdb
cpu: Apple M1 Max
                                               │ target1.txt  │               pr1.txt               │
                                               │    sec/op    │    sec/op     vs base               │
FakeDB_NewestBlockID/newest_block_id-10          194.2µ ± ∞ ¹   203.0µ ± ∞ ¹        ~ (p=0.690 n=5)
FakeDB_WriteBlocks/repeated_writes-10             5.637 ± ∞ ¹    5.765 ± ∞ ¹        ~ (p=0.841 n=5)
FakeDB_WriteBlocks/batched_writes-10              2.651 ± ∞ ¹    2.617 ± ∞ ¹        ~ (p=0.310 n=5)
TestDB_FilterEvents/AddressCriteriaFilter-10      12.24 ± ∞ ¹    14.11 ± ∞ ¹  +15.32% (p=0.008 n=5)
TestDB_FilterEvents/TopicCriteriaFilter-10        96.07 ± ∞ ¹    96.12 ± ∞ ¹        ~ (p=0.690 n=5)
TestDB_FilterEvents/EventLimit-10                 2.010 ± ∞ ¹    1.958 ± ∞ ¹        ~ (p=0.095 n=5)
TestDB_FilterEvents/EventLimitDesc-10             2.747 ± ∞ ¹    2.670 ± ∞ ¹        ~ (p=0.151 n=5)
TestDB_FilterEvents/EventRange-10                 1.335 ± ∞ ¹    1.256 ± ∞ ¹        ~ (p=0.310 n=5)
TestDB_FilterEvents/EventRangeDesc-10             1.285 ± ∞ ¹    1.245 ± ∞ ¹   -3.16% (p=0.008 n=5)
TestDB_FilterTransfers/TransferCriteria-10       171.0µ ± ∞ ¹   166.4µ ± ∞ ¹        ~ (p=0.056 n=5)
TestDB_FilterTransfers/TransferCriteriaDesc-10   173.6µ ± ∞ ¹   166.4µ ± ∞ ¹        ~ (p=0.056 n=5)
TestDB_FilterTransfers/Ranged500K-10             337.2m ± ∞ ¹   339.1m ± ∞ ¹        ~ (p=1.000 n=5)
TestDB_FilterTransfers/Ranged500KDesc-10         338.1m ± ∞ ¹   333.6m ± ∞ ¹        ~ (p=0.056 n=5)
geomean                                          291.4m         290.8m         -0.22%
¹ need >= 6 samples for confidence interval at level 0.95

                                               │  target1.txt  │               pr1.txt               │
                                               │     B/op      │     B/op       vs base              │
FakeDB_NewestBlockID/newest_block_id-10          6.640Ki ± ∞ ¹   6.639Ki ± ∞ ¹       ~ (p=0.460 n=5)
FakeDB_WriteBlocks/repeated_writes-10            140.4Mi ± ∞ ¹   140.4Mi ± ∞ ¹       ~ (p=1.000 n=5)
FakeDB_WriteBlocks/batched_writes-10             136.6Mi ± ∞ ¹   136.6Mi ± ∞ ¹       ~ (p=0.690 n=5)
TestDB_FilterEvents/AddressCriteriaFilter-10     613.0Mi ± ∞ ¹   613.0Mi ± ∞ ¹       ~ (p=0.151 n=5)
TestDB_FilterEvents/TopicCriteriaFilter-10       610.3Mi ± ∞ ¹   610.3Mi ± ∞ ¹       ~ (p=0.127 n=5)
TestDB_FilterEvents/EventLimit-10                639.9Mi ± ∞ ¹   639.9Mi ± ∞ ¹       ~ (p=0.111 n=5)
TestDB_FilterEvents/EventLimitDesc-10            677.2Mi ± ∞ ¹   677.2Mi ± ∞ ¹  +0.00% (p=0.048 n=5)
TestDB_FilterEvents/EventRange-10                320.3Mi ± ∞ ¹   320.3Mi ± ∞ ¹       ~ (p=0.548 n=5)
TestDB_FilterEvents/EventRangeDesc-10            320.3Mi ± ∞ ¹   320.3Mi ± ∞ ¹       ~ (p=0.206 n=5)
TestDB_FilterTransfers/TransferCriteria-10       39.86Ki ± ∞ ¹   39.86Ki ± ∞ ¹       ~ (p=0.175 n=5)
TestDB_FilterTransfers/TransferCriteriaDesc-10   39.86Ki ± ∞ ¹   39.86Ki ± ∞ ¹  -0.00% (p=0.024 n=5)
TestDB_FilterTransfers/Ranged500K-10             70.44Mi ± ∞ ¹   70.44Mi ± ∞ ¹       ~ (p=0.095 n=5)
TestDB_FilterTransfers/Ranged500KDesc-10         70.44Mi ± ∞ ¹   70.44Mi ± ∞ ¹       ~ (p=0.095 n=5)
geomean                                          29.94Mi         29.94Mi        -0.00%
¹ need >= 6 samples for confidence interval at level 0.95

                                               │ target1.txt  │               pr1.txt                │
                                               │  allocs/op   │  allocs/op    vs base                │
FakeDB_NewestBlockID/newest_block_id-10           134.0 ± ∞ ¹    134.0 ± ∞ ¹       ~ (p=1.000 n=5) ²
FakeDB_WriteBlocks/repeated_writes-10            2.728M ± ∞ ¹   2.728M ± ∞ ¹       ~ (p=0.222 n=5)
FakeDB_WriteBlocks/batched_writes-10             2.516M ± ∞ ¹   2.516M ± ∞ ¹       ~ (p=0.690 n=5)
TestDB_FilterEvents/AddressCriteriaFilter-10     20.00M ± ∞ ¹   20.00M ± ∞ ¹       ~ (p=0.722 n=5)
TestDB_FilterEvents/TopicCriteriaFilter-10       20.16M ± ∞ ¹   20.16M ± ∞ ¹       ~ (p=0.325 n=5)
TestDB_FilterEvents/EventLimit-10                21.73M ± ∞ ¹   21.73M ± ∞ ¹  +0.00% (p=0.040 n=5)
TestDB_FilterEvents/EventLimitDesc-10            20.04M ± ∞ ¹   20.04M ± ∞ ¹  +0.00% (p=0.024 n=5)
TestDB_FilterEvents/EventRange-10                10.65M ± ∞ ¹   10.65M ± ∞ ¹  +0.00% (p=0.048 n=5)
TestDB_FilterEvents/EventRangeDesc-10            10.65M ± ∞ ¹   10.65M ± ∞ ¹       ~ (p=0.278 n=5)
TestDB_FilterTransfers/TransferCriteria-10       1.424k ± ∞ ¹   1.424k ± ∞ ¹       ~ (p=1.000 n=5) ²
TestDB_FilterTransfers/TransferCriteriaDesc-10   1.424k ± ∞ ¹   1.424k ± ∞ ¹       ~ (p=1.000 n=5) ²
TestDB_FilterTransfers/Ranged500K-10             2.607M ± ∞ ¹   2.607M ± ∞ ¹  +0.00% (p=0.040 n=5)
TestDB_FilterTransfers/Ranged500KDesc-10         2.607M ± ∞ ¹   2.607M ± ∞ ¹       ~ (p=0.079 n=5)
geomean                                          899.5k         899.5k        -0.00%
¹ need >= 6 samples for confidence interval at level 0.95
² all samples are equal

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• New and existing E2E tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• I have not added any vulnerable dependencies to my code

[codecov-commenter]

Codecov Report

❌ Patch coverage is 39.58333% with 29 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
logdb/logdb.go	36.95%	27 Missing and 2 partials ⚠️

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