Confusing configuration: CONF_TBL_PREFIX versus MONGO_COLLECTION_PREFIX versus RyaInstance

These THREE constants 1 2 3 are somewhat redundant. They are the the same as the Rya Instance in most cases. For MongoDB, the table prefix2 may be used incorrectly instead of the collection prefix1.

They should probably be melded into one config key and method and be called the rya instance. The RyaDetails has this concept. There is a ConfigUtil.getTablePrefix() and TablePrefixLayoutStrategy.getTablePrefix() that should be refactored as part of this.

Some have suggested that the collection prefix is not needed at all since it is scoped inside a single Mongo Database which contains only one rya instance.

1

 conf.set(MongoDBRdfConfiguration.MONGO_COLLECTION_PREFIX, "rya_");

2

conf.set(RdfCloudTripleStoreConfiguration.CONF_TBL_PREFIX, "rya_");

3

TablePrefixLayoutStrategy.tablePrefix = RdfCloudTripleStoreConstants.TBL_PRFX_DEF; // = "rya_";

Some unit tests set them as different values.

Look at extras/indexing/src/main/java/mvm/rya/sail/config/RyaSailFactory.java around line 73 for a good example of the confusion. Look for this comment:
// XXX Should be MongoDBRdfConfiguration.MONGO_COLLECTION_PREFIX inside the if below.

One more redundant field: TablePrefixLayoutStrategy.tablePrefix See RYA-138
It is defaults to "rya_" but has a getter and setter.

TablePrefixLayoutStrategy implements TableLayoutStrategy{
    private String tablePrefix = RdfCloudTripleStoreConstants.TBL_PRFX_DEF;