[TAJO-610] Refactor Column class

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.8.0
• Component/s: Catalog
• Assignee: Hyunsik Choi
• Reporter: Hyunsik Choi
• Created: 19/Feb/14 16:12
• Updated: 20/Feb/14 11:16
• Resolved: 20/Feb/14 11:10

Description

Column class has some ambiguous methods and some complex logics.

This patch simplifies and refactors Column class as follows:

• Rename getColumnNum() to size()
• Remove qualifier variable from Column and ColumnProto
• Rename getColumnName to getSimpleName
• Move some codes for qualification and simple name to CatalogUtil and refactor them for common identifiers including database, table and column names
• Change Column as an immutable object

Issue Links

• blocks: TAJO-516 Add default database name 'default' to Tajo