CrossDB Index is used to implement database Primary Key and accelerate query.
HASHindex has highest O(1) performance. It's optimized a lot to achieve best performance.
HASHindex can dynamically scale with table rows number to get high performance.
HASHindex only supports exact match.
- Use flag
RBTREEindex is almost the same with popular RDBMS BTree, which is core index engine of RDBMS.
RBTREEindex can support exact match, range match and leftmost prefix match with multiple-column.
- Default index is
- If one query matches both HASH index and RBTREE index, then Hash index is selected in most cases.
- You can create
HASHindex for high performance query and
RBTREEindex for normal performance queries.
- Index is not free, it occupies space and all inexes may be updated during INSERT/UPDATE/DELET row.
- If index is unique, please set
- For unique index, either
updatewill check row is unique.
- You can do any query on any fields combination without index.
- Create index only when the query calls frequency is high and requires performance.