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Type:
Improvement
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Resolution: Won't Fix
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Priority:
Major - P3
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None
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Affects Version/s: None
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Component/s: Storage
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None
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v4.0, v3.6
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Storage NYC 2018-12-31
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(copied to CRM)
KVStorageEngine::listDatabases() will skip databases that don't have any collections:
kv_storage_engine.cpp
void KVStorageEngine::listDatabases(std::vector<std::string>* out) const { stdx::lock_guard<stdx::mutex> lk(_dbsLock); for (DBMap::const_iterator it = _dbs.begin(); it != _dbs.end(); ++it) { if (it->second->isEmpty()) continue; out->push_back(it->first); } }
I'm unsure of why this is, but there is a legitimate use case for listing empty databases. Consider the following sequence of user operations – the user is misled into thinking the database "bloop" doesn't exist because it is totally omitted from the listDatabases output even though the database does, in fact, exist:
> use bloop
switched to db bloop
> db.coll.insert({x: 1});
WriteResult({ "nInserted" : 1 })
> show dbs
admin 0.000GB
bloop 0.000GB
config 0.000GB
local 0.000GB
> assert(db.coll.drop());
true
> show dbs
admin 0.000GB
config 0.000GB
local 0.000GB
> use BLOOP
switched to db BLOOP
> db.coll.insert({x: 1})
WriteResult({
"nInserted" : 0,
"writeError" : {
"code" : 13297,
"errmsg" : "db already exists with different case already have: [bloop] trying to create [BLOOP]"
}
})
- depends on
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- Closed
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