Vladimir Sitnikov created CALCITE-3786: ------------------------------------------
Summary: Add Digest (HashStrategy?) interface to enable efficient hashCode/equals for RexNode, RelNode Key: CALCITE-3786 URL: https://issues.apache.org/jira/browse/CALCITE-3786 Project: Calcite Issue Type: New Feature Components: core Affects Versions: 1.21.0 Reporter: Vladimir Sitnikov Current digests for RexNode, RelNode, RelType, and similar cases use String concatenation. It is easy to implement, however, it has drawbacks: 1) String objects cannot be reused. For instance, RexCall has operands, however, the digest is duplicated. It causes extra memory use, and extra CPU for string copying 2) There's no way to have multiple #toString() methods. RelType might need multiple digests: "including field names", "excluding field names". Suggested resolution might be behind the lines of {code:java} class Digest { // immutable final int hashCode; // speedup hashCode and equals final Object[] contents; // The values are either other Digest objects or Strings } {code} Then the digest for RexCall could be the bits relevant to RexCall itself + digests of the operands (which can be reused as is) -- This message was sent by Atlassian Jira (v8.3.4#803005)