[YSQL] Keyspace already exists issue caused by OID collision + X

[yifanguan]

Jira Link: DB-5849

Description

This is another side-effect issue caused by OID collision issue #16130 + X.
First,
It looks like we end up never clean up the namespace_ids_map_ after deleting a YSQL database.
In catalog_manager.cc

// Remove namespace from CatalogManager name mapping.  Will remove ID map after all Tables gone.
  {
    LockGuard lock(mutex_);
    if (namespace_names_mapper_[database->database_type()].erase(database->name()) < 1) {
      LOG(WARNING) << Format("Could not remove namespace from maps, name=$0, id=$1",
                             database->name(), database->id());
    }
  }

And a small repro on a fresh cluster to illustrate this issue:

connection 1 on node1:
\c yugabyte
CREATE DATABASE qqq; -- 16384
CREATE DATABASE ooo; -- 16385
DROP DATABASE qqq;

connection 2 on node2:
\c ooo
CREATE DATABASE ppp; -- 16384
ERROR:  Keyspace 'ppp' already exists

Workaround is to retry the failed create database statement.

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[Arjun-yb]

@yifanguan
in 2.18.0.0-b14, We observed

Failed to execute task {"sleepAfterMasterRestartMillis":180000,"sleepAfterTServerRestartMillis":180000,"nodeExporterUser":"prometheus","universeUUID":"c01f90e1-c553-496e-bc74-3572fd536dc6","enableYbc":false,"installYbc":false,"ybcInstalled":false,"encryptionAtRestConfig":{"encryptionAtRestEnabled":false,"opType":"UNDEFINED","type":"DATA_KEY"},"communicationPorts":{"masterHttpPort":7000,"masterRpcPort":7100,"tserverHttpPort":9000,"tserverRpcPort":9100,"ybControllerHttpPort":14000,"ybControllerrRpcPort":18018,"redisS..., hit error:

Task id 0ba4d5ed-0073-4b49-846b-0f7099070afd_PGSQL_TABLE_TYPE_non_colocated_db status: Failed with error COMMAND_FAILED.

in testysqltspcmvandbr test
https://jenkins.dev.yugabyte.com/view/Test%20Jobs/job/itest-system-developer/5177/artifact/logs/2.18.0.0_testysqltspcmvandbr-aws-rf3_20230417_111840/testysqltspcmvandbr-aws-rf3pvlzfvfs.log
Raised issue: #16642
cc: @kripasreenivasan @zlareb1-yb

[yifanguan]

Resolved by commit 1c781b7