I have a variation on the classic "why scan that table?" When the query plan mentions SCAN TABLE jsondumps does it mean a full table scan or just a partial table scan? If full, why? I have an index.

Background: the tables

• jsondumps - two columns, content json and fileSampleId integer
• FileSamplings
• AttrKeys

sqlite> .schema jsondumps
CREATE TABLE jsondumps (
                           ID INTEGER PRIMARY KEY not null,
                           fileSampleId INTEGER NOT NULL,
                           content JSON
                           );
CREATE INDEX JSONDUMPS_FILESAMPLEID on jsondumps(fileSampleId);

When the query plan mentions SCAN TABLE jsondumps does it mean a full table scan or just a partial table scan? If full, why? I have an index.

sqlite>  create temp table newnumvalues as
   ...>    select fileSamplings.ID as fileSamplingsId, AttrKeys.ID as AttrKeysId, json_tree.atom as numval
   ...>      from
   ...>      FileSamplings
   ...>      join
   ...>      jsondumps,json_tree(jsondumps.content)
   ...>      on jsondumps.fileSampleId =FileSamplings.ID
   ...>      join AttrKeys on AttrKeys.name = fullkey
   ...>     where type = 'real' or type = 'integer'
   ...>       and FileSamplings.sampleId=46 ;
QUERY PLAN
|--SCAN TABLE jsondumps
|--SEARCH TABLE FileSamplings USING INTEGER PRIMARY KEY (rowid=?)
|--SCAN TABLE json_tree VIRTUAL TABLE INDEX 1:
`--SEARCH TABLE AttrKeys USING COVERING INDEX ATTR_NAME_IDX (name=?)