After installing hive, if the first thing you did was run hive, hive attempted to create/initialize the metastore_db, but apparently might not get it right. On that initial run, maybe you saw your error:

Exception in thread "main" java.lang.RuntimeException: Hive metastore database is not initialized. Please use schematool (e.g. ./schematool -initSchema -dbType ...) to create the schema. If needed, don't forget to include the option to auto-create the underlying database in your JDBC connection string (e.g. createDatabaseIfNotExist=true for mysql)

Running hive, even though it fails, creates a metastore_db directory in the directory from which you ran hive:

ubuntu15-laptop: ~ $>ls -l |grep meta
drwxrwxr-x 5 testuser testuser 4096 Apr 14 12:44 metastore_db

So when you then tried running

ubuntu15-laptop: ~ $>schematool -initSchema -dbType derby

The metastore already existed, but not in complete form.

Soooooo the answer is:

1. Before you run hive for the first time, run

   schematool -initSchema -dbType derby

2. If you already ran hive and then tried to initSchema and it's failing:

   mv metastore_db metastore_db.tmp

3. Re run

   schematool -initSchema -dbType derby

4. Run hive again

**Also of note: if you change directories, the metastore_db created above won't be found! I'm sure there's a good reason for this that I don't know yet because I'm literally trying to use hive for the first time today. Ahhh here's information on this: metastore_db created wherever I run Hive