isu_conditions取得部分にあるN+1問題を解消

[pinkumohikan]

refs #1

下記クエリに対するチューニング

# Query 1: 18.98 QPS, 0.05x concurrency, ID 0x931A992E852C61FC6D46141A39DEF4FE at byte 142186342
# Scores: V/M = 0.00
# Time range: 2024-10-05 15:57:28 to 16:40:00
# Attribute    pct   total     min     max     avg     95%  stddev  median
# ============ === ======= ======= ======= ======= ======= ======= =======
# Count          6   48432
# Exec time     50    134s     4us    47ms     3ms    10ms     4ms     1ms
# Lock time     17      1s       0     8ms    27us    52us    65us    22us
# Rows sent     84   5.34M       0     760  115.60  420.77  134.10   69.19
# Rows examine  71 273.05M       0  30.09k   5.77k  21.38k   6.87k   3.35k
# Rows affecte   0       0       0       0       0       0       0       0
# Bytes sent    35 977.28M     589 139.25k  20.66k  76.03k  23.69k  12.50k
# Query size     4   5.31M     115     115     115     115       0     115
# Boolean:
# QC hit        10% yes,  89% no
# String:
# Databases    isucondition
# Hosts        ip-172-31-46-68.ap-northeast-1.compute.inter...
# Users        isucon
# Query_time distribution
#   1us  #####
#  10us  ######
# 100us  ######################################
#   1ms  ################################################################
#  10ms  ######
# 100ms
#    1s
#  10s+
# Tables
#    SHOW TABLE STATUS FROM `isucondition` LIKE 'isu_condition'\G
#    SHOW CREATE TABLE `isucondition`.`isu_condition`\G
# EXPLAIN /*!50100 PARTITIONS*/
SELECT * FROM `isu_condition` WHERE `jia_isu_uuid` = '48b8339b-9123-4a75-b801-59b3079458d1' ORDER BY timestamp DESC\G