dumpling is slow in 1M tables case

[lance6716]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

prepare a large cluster with many database, each database has a small number of tables. Then use dumpling to dump a database with 2 tables

2. What did you expect to see? (Required)

dump is fast, because only 2 tables will be dumped

3. What did you see instead (Required)

tiup dumpling:nightly -u root -P 4000 -h [10.104.100.98](http://10.104.100.98/) --filetype csv -t 16 -r 200000 -F 256MiB --database sb10wnormal1
[2024/12/02 06:50:54.641 +00:00] [INFO] [dump.go:152] ["begin to run Dump"] [conf="{\"s3\":{\"endpoint\":\"\",\"region\":\"\",\"storage-class\":\"\",\"sse\":\"\",\"sse-kms-key-id\":\"\",\"acl\":\"\",\"access-key\":\"\",\"secret-access-key\":\"\",\"session-token\":\"\",\"provider\":\"\",\"force-path-style\":true,\"use-accelerate-endpoint\":false,\"role-arn\":\"\",\"external-id\":\"\",\"object-lock-enabled\":false},\"gcs\":{\"endpoint\":\"\",\"storage-class\":\"\",\"predefined-acl\":\"\",\"credentials-file\":\"\"},\"azblob\":{\"endpoint\":\"\",\"account-name\":\"\",\"account-key\":\"\",\"access-tier\":\"\",\"sas-token\":\"\",\"encryption-scope\":\"\",\"encryption-key\":\"\"},\"SpecifiedTables\":false,\"AllowCleartextPasswords\":false,\"SortByPk\":true,\"NoViews\":true,\"NoSequences\":true,\"NoHeader\":false,\"NoSchemas\":false,\"NoData\":false,\"CompleteInsert\":false,\"TransactionalConsistency\":true,\"EscapeBackslash\":true,\"DumpEmptyDatabase\":true,\"PosAfterConnect\":false,\"CompressType\":0,\"Host\":\"[10.104.100.98](http://10.104.100.98/)\",\"Port\":4000,\"Threads\":16,\"User\":\"root\",\"Security\":{\"CAPath\":\"\",\"CertPath\":\"\",\"KeyPath\":\"\"},\"LogLevel\":\"info\",\"LogFile\":\"\",\"LogFormat\":\"text\",\"OutputDirPath\":\"./export-2024-12-02T06:50:54Z\",\"StatusAddr\":\":8281\",\"Snapshot\":\"454327600314580994\",\"Consistency\":\"snapshot\",\"CsvNullValue\":\"\\\\N\",\"SQL\":\"\",\"CsvSeparator\":\",\",\"CsvDelimiter\":\"\\\"\",\"CsvLineTerminator\":\"\\r\\n\",\"Databases\":[\"sb10wnormal1\"],\"Where\":\"\",\"FileType\":\"csv\",\"ServerInfo\":{\"ServerType\":3,\"ServerVersion\":\"8.5.0-alpha-256-gec288d95a3\",\"HasTiKV\":true},\"Rows\":200000,\"ReadTimeout\":900000000000,\"TiDBMemQuotaQuery\":0,\"FileSize\":268435456,\"StatementSize\":1000000,\"SessionParams\":{\"tidb_snapshot\":\"454327600314580994\"},\"Tables\":{},\"CollationCompatible\":\"loose\",\"CsvOutputDialect\":0,\"IOTotalBytes\":null,\"Net\":\"\"}"]
...
[2024/12/02 07:05:42.661 +00:00] [ERROR] [main.go:78] ["dump failed error stack info"] [error="sql: SELECT COUNT(1) as c FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE='SEQUENCE': Error 9006 (HY000): GC life time is shorter than transaction duration, transaction starts at 2024-12-02 06:50:38.718 +0000 UTC, GC safe point is 2024-12-02 06:50:54.618 +0000 UTC"] [errorVerbose="Error 9006 (HY000): GC life time is shorter than transaction duration, transaction starts at 2024-12-02 06:50:38.718 +0000 UTC, GC safe point is 2024-12-02 06:50:54.618 +0000 UTC\nsql: SELECT COUNT(1) as c FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE='SEQUENCE'\[ngithub.com/pingcap/tidb/dumpling/export.CheckIfSeqExists\n\tgithub.com/pingcap/tidb/dumpling/export/sql.go:932\ngithub.com/pingcap/tidb/dumpling/export.prepareTableListToDump\n\tgithub.com/pingcap/tidb/dumpling/export/dump.go:1153\ngithub.com/pingcap/tidb/dumpling/export.(*Dumper).Dump\n\tgithub.com/pingcap/tidb/dumpling/export/dump.go:218\nmain.main\n\t./main.go:75\nruntime.main\n\truntime/proc.go:272\nruntime.goexit\n\truntime/asm_amd64.s:1700](http://ngithub.com/pingcap/tidb/dumpling/export.CheckIfSeqExists/n/tgithub.com/pingcap/tidb/dumpling/export/sql.go:932/ngithub.com/pingcap/tidb/dumpling/export.prepareTableListToDump/n/tgithub.com/pingcap/tidb/dumpling/export/dump.go:1153/ngithub.com/pingcap/tidb/dumpling/export.(*Dumper).Dump/n/tgithub.com/pingcap/tidb/dumpling/export/dump.go:218/nmain.main/n/t./main.go:75/nruntime.main/n/truntime/proc.go:272/nruntime.goexit/n/truntime/asm_amd64.s:1700)"]

a query is slow, which meet other error and fails the dump

4. What is your TiDB version? (Required)