SchemaCache dosen't work

[JeffGuKang]

Issue Description

CREATE TABLE IF NOT EXISTS "_SCHEMA" ( "className" varChar(120), "schema" jsonb, "isParseClass" bool, PRIMARY KEY ("className") )

called continually. with SELECT * FROM "_SCHEMA"

And DB Connection increased also.

I found this query from the parse server source

I am not sure why this happens and what is wrong with my code. So I shared my issue.

Query log

...
2020-03-07 09:55:08.372 KST [40465] LOG:  duration: 0.151 ms  statement: SELECT * FROM "_SCHEMA"
2020-03-07 09:55:08.373 KST [40465] LOG:  duration: 0.184 ms  statement: SELECT * FROM "Info" WHERE "objectId" = 'Ap9l9l0enC' AND ("_rperm" IS NULL OR "_rperm" && ARRAY['*','*','xO7kxBDsZO'])   
2020-03-07 09:55:08.374 KST [40465] LOG:  duration: 0.040 ms  statement: CREATE TABLE IF NOT EXISTS "_SCHEMA" ( "className" varChar(120), "schema" jsonb, "isParseClass" bool, PRIMARY KEY ("className") )
2020-03-07 09:55:08.375 KST [40465] LOG:  duration: 0.140 ms  statement: SELECT * FROM "_SCHEMA"
2020-03-07 09:55:08.376 KST [40465] LOG:  duration: 0.092 ms  statement: SELECT * FROM "Info" WHERE "objectId" = 'Ap9l9l0enC'   
2020-03-07 09:55:08.380 KST [40465] LOG:  duration: 0.068 ms  statement: CREATE TABLE IF NOT EXISTS "_SCHEMA" ( "className" varChar(120), "schema" jsonb, "isParseClass" bool, PRIMARY KEY ("className") )
2020-03-07 09:55:08.381 KST [40465] LOG:  duration: 0.158 ms  statement: SELECT * FROM "_SCHEMA"
2020-03-07 09:55:08.382 KST [40465] LOG:  duration: 0.103 ms  statement: SELECT * FROM "Photo" WHERE "objectId" = 'eGvqdUDF7h'   
...

Steps to reproduce

PostgreSQL RDS <=> EC2 Parse Server with LiveQuery
Redis <=>

I am using Parse.Object.registerSubclass Parse Classes as below.

interface PetParams {
...
}

export class Pet extends Parse.Object<PetParams> {
  constructor(params?: PetParams) {
    super('Pet', params) 
  }

  deleteSelf = (id, options: Parse.Object.DestroyOptions) => {
    this.id = id

    return this.destroy(options)
  }
}

Expected Results

Do not call SELECT * FROM "_SCHEMA" query continually

Actual Outcome

Environment Setup

• Server

  • parse-server version (Be specific! Don't say 'latest'.) : [4.0.1]
  • Operating System: [Node.js running on 64bit Amazon Linux/4.13.0]
  • Hardware: []
  • Localhost or remote server? (AWS, Heroku, Azure, Digital Ocean, etc): [AWS]

• Database

  • PostgreSQL version: [11.4 ~ 11.5]
  • Storage engine: [RDS, Redis]
  • Hardware: []
  • Localhost or remote server? (AWS): [AWS]

Logs/Trace

No Parse log

[dplewis]

Is burst a keyword in postgres? Can you provide a link?

[JeffGuKang]

Is burst a keyword in postgres? Can you provide a link?

Sorry. I changed the title and updated query log.

[JeffGuKang]

getAllClasses function is called again and again.

  async getAllClasses() {
    const self = this;
    return this._client.task('get-all-classes', async t => {
      await self._ensureSchemaCollectionExists(t);
      return await t.map('SELECT * FROM "_SCHEMA"', null, row => toParseSchema(_objectSpread({
        className: row.className
      }, row.schema)));
    });
  } // Return a promise for the schema with the given name, in Parse format. If
  // this adapter doesn't know about the schema, return a promise that rejects with
  // undefined as the reason.

I think caching has a problem.

[JeffGuKang]

enableSingleSchemaCache: true option can solve this problem. thanks @yomybaby.
But why the options' default is false? It makes a lot of useless query.

[JeffGuKang]

Refer #6476

[JeromeDeLeon]

Although this was closed, if you look at the #5612 , @dplewis stated that it should be true by default but few tests failed and he will do a separate PR for it.