Bug #96944 | Default value of "threads" option of "Parallel Table Import Utility" | ||
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Submitted: | 19 Sep 2019 9:35 | Modified: | 7 Oct 2019 10:59 |
Reporter: | MAKOTO FUKUMOTO | Email Updates: | |
Status: | Not a Bug | Impact on me: | |
Category: | MySQL Server: Document Store: MySQL Shell | Severity: | S3 (Non-critical) |
Version: | 8.0.17 | OS: | CentOS |
Assigned to: | CPU Architecture: | Any | |
Tags: | mysql shell |
[19 Sep 2019 9:35]
MAKOTO FUKUMOTO
[19 Sep 2019 11:25]
MySQL Verification Team
Hello MAKOTO-San, Thank you for the report and feedback. regards, Umesh
[7 Oct 2019 10:59]
Krzysztof Grzadziel
Posted by developer: There is no reason to spawn more import threads than needed. Relation between threads, bytesPerChunk and imported file size is following: min{max{1, threads}, chunks}} where: - threads - number of threads - chunks - (file_size / bytesPerChunk) + 1 i.e. we need at least one thread, but no more threads than file chunks. You see 4 spawned threads because your import file has size roughly between 150M and 200M (with default bytesPerChunk equal to 50M). It is not a bug, but it would be nice to have relation formula in documentation.