postgresql 建立索引：ERROR: operator class "gin_trgm_ops" does not exist for access method "gin"

g_trgm is an extension, so:

CREATE EXTENSION pg_trgm;

If you get the following error

ERROR: could not open extension control file ".../extension/pg_trgm.control":
No such file or directory"

then you need to install the module for your operating system

• Ubuntu/Debian:

  sudo apt install postgresql-contrib

• Redhat/Centos

  sudo yum install postgresql10-contrib

• Fedora

  sudo dnf install postgresql-contrib