Explanation of lucene-1.0: Too many open files error

If one encounters a ‘Too many open files’ error in their $NEO4J_HOME/logs/debug.log similar to Caused by: java.nio.file.FileSystemException: /data/neo4j/db/schema/index/lucene_native-2.0/1612/lucene-1.0: Too many open files at sun.nio.fs.UnixException.translateToIOException(UnixException.java:91) at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:102) at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:107) at sun.nio.fs.UnixFileSystemProvider.newDirectoryStream(UnixFileSystemProvider.java:427) at java.nio.file.Files.newDirectoryStream(Files.java:457) this can be addressed by setting in your… Read more →

Using explicit indexes for text search

Please note that in Neo4j 3.5 FullText search is available in Neo4j as part of Cypher stored procedures. More documentation is found here: https://neo4j.com/docs/cypher-manual/3.5/schema/index/#schema-index-fulltext-search. As of Neo4j 3.4.x, the schema index is optimal for indexing exact property values, but does… Read more →

Fulltext search in Neo4j

Please note that in Neo4j 3.5 fulltext search is available in Neo4j as part of Cypher stored procedures. More documentation is found here: https://neo4j.com/docs/cypher-manual/3.5/schema/index/#schema-index-fulltext-search. Fulltext search in Neo4j is supported by means of fulltext schema indexes. Fulltext schema indexes are… Read more →

Using Cypher to generate Cypher statements to recreate indexes and constraints

The following can be used to extract index defintions and constraint defintions from an existing database and the resultant output can be played back on another Neo4j database. For example with the :play movies dataset as when run from the… Read more →