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Full-text index restrictions

Caution

This topic introduces the restrictions for full-text indexes. Please read the restrictions very carefully before using the full-text indexes.

For now, full-text search has the following limitations:

  • Currently, full-text search supports LOOKUP statements only.
  • Uppercase letters are not allowed in a full-text index name.
  • The maximum indexing string length is 256 bytes. The part of data that exceeds 256 bytes will not be indexed.
  • Full-text search is native-index-dependent. You need to first create an index for tags/edge types and then you can use the full-text index feature.
  • If there is a full-text index on the tag/edge type, the tag/edge type cannot be deleted or modified.
  • One tag/edge type can only have one full-text index.
  • The type of properties must be string.
  • Full-text index can not be applied to search multiple tags/edge types.
  • Sorting for the returned results of the full-text search is not supported. Data is returned in the order of data insertion.
  • Full-text index can not search properties with value NULL.
  • Elastic Search creates the corresponding index automatically when writing data. The error text search not found will be displayed when users created a full-text index but no corresponding data was written.
  • Altering Elasticsearch indexes is not supported at this time.
  • The pipe operator is not supported.
  • WHERE clauses supports full-text search only working on single terms.
  • Full-text indexes are not deleted together with the graph space.
  • Make sure that you start the Elasticsearch cluster and Nebula Graph at the same time. If not, the data writing on the Elasticsearch cluster can be incomplete.
  • Do not contain ' or \ in the vertex or edge values. If not, an error will be caused in the Elasticsearch cluster storage.
  • It may take a while for Elasticsearch to create indexes. If Nebula Graph warns no index is found, wait for the index to take effect (however, the waiting time is unknown and there is no code to check).
  • NebulaGraph clusters deployed with K8s do not support the full-text search feature.

Last update: December 6, 2022