Multi-faceted search using healthcare data

Create and alter search indexes using CQL index management commands.

1. Launch cqlsh on a search node:
   1. Determine which nodes in the cluster are running a search workload:

      dsetool status

      Tip: DSE Search operations are available only on search-enabled nodes. DataStax recommends single workload datacenters.
      The following example shows a development environment where all nodes in the cluster are in the same physical location, on the same rack, and the nodes have been separated into datacenters based on their workloads:

      DC: Main       Workload: Cassandra       Graph: no
      ======================================================
      Status=Up/Down
      |/ State=Normal/Leaving/Joining/Moving
      --   Address          Load             Owns               VNodes       Rack         Health [0,1]
      UN   10.10.10.111   15.51 MiB        ?                    8            rack1        0.90
      UN   10.10.10.113   19.51 MiB        ?                    8            rack1        0.90
      
      DC: Search            Workload: Search          Graph: no
      ======================================================
      Status=Up/Down
      |/ State=Normal/Leaving/Joining/Moving
      --   Address          Load             Owns               VNodes       Rack         Health [0,1]
      UN   10.10.10.108   18.13 MiB        ?                    8            rack1        0.90
      UN   10.10.10.110   17.4 MiB         ?                    8            rack1        0.90

   2. Launch a cqlsh session on a search node from the directory that contains the health_data.csv:

      cd ~ && cqlsh -k healthcare

      A CQL sessions starts using the demo keyspace.

      Connected to cluster1 at 10.10.10.108:9042.
      [cqlsh 5.0.1 | Cassandra 3.11.0.1805 | DSE 5.1.3 | CQL spec 3.4.4 | Native protocol v4]
      Use HELP for help.
      cqlsh:healthcare>

      Tip: The active keyspace name appears in the cqlsh prompt.
2. Set up the health_data table with data:
   1. Create the table:

      USE healthcare;
      
      // START-create-table
      CREATE TABLE IF NOT EXISTS healthcare.health_data (
      "id" INT,
      "num_smokers" INT,
      "age" INT,
      "age_unit" VARCHAR,
      "age_months" INT,
      "major_medical_coverage" VARCHAR,
      "dental_coverage" VARCHAR,
      "routine_medical_coverage" VARCHAR,
      "employer_paid_plan" VARCHAR,
      "secondary_smoke" VARCHAR,
      "county" VARCHAR,
      "screening_month" VARCHAR,
      "pets" VARCHAR,
      "asthma" VARCHAR,
      "bronchitis" VARCHAR,
      "goiter" VARCHAR,
      "hay_fever" VARCHAR,
      "thyroid_disease" VARCHAR,
      "chronic_bronchitis" VARCHAR,
      "diagnosed_asthma" VARCHAR,
      "diagnosed_cataracts" VARCHAR,
      "diagnosed_emphysema" VARCHAR,
      "diagnosed_goiter" VARCHAR,
      "diagnosed_gout" VARCHAR,
      "diagnosed_hay_fever" VARCHAR,
      "diagnosed_lupus" VARCHAR,
      "diagnosed_other_cancer" VARCHAR,
      "diagnosed_skin_cancer" VARCHAR,
      "diagnosed_stroke" VARCHAR,
      "diagnosed_thyroid_disease" VARCHAR,
      "diagnosed_congestive_heart_failure" VARCHAR,
      "ethnicity" VARCHAR,
      "exam_status" VARCHAR,
      "family_sequence" INT,
      "family_size" INT,
      "fips" VARCHAR,
      "grade_completed" VARCHAR,
      "household_size" INT,
      "health_status" VARCHAR,
      "marital_status" VARCHAR,
      "bird" VARCHAR,
      "cat" VARCHAR,
      "dog" VARCHAR,
      "fish" VARCHAR,
      "other_pet" VARCHAR,
      "race" VARCHAR,
      "race_ethnicity" VARCHAR,
      "gender" VARCHAR,
      "birthplace" VARCHAR,
      "annual_income_20000" VARCHAR,
      "income_group" INT,
      "monthly_income_total" INT,
      PRIMARY KEY ("id", "age"))
      WITH gc_grace_seconds = 0;
      // END-create-table

      Tip: After loading data that contains null values, temporarily set the grace period to zero to clean up tombstones.
   2. Use DataStax Bulk Loader to load data from the health_data.csv file:

      dsbulk load -f dsbulkConfigFile.conf -url health_data.csv -k healthcare -t health_data \
                  -header false --schema.allowExtraFields true --schema.allowMissingFields true

      Note: If the health_data.csv is not in the directory where you launch cqlsh, specify the full path to the file. Also, the dsbulkConfigFile.conf file referenced in the dsbulk command includes the schema.mapping definition for the health_data table. For example:

      schema.mapping = "0=id, 1=num_smokers, 2=age, 3=age_unit, 4=age_months, 5=major_medical_coverage, 
      6=dental_coverage, 7=routine_medical_coverage, 8=employer_paid_plan, 9=secondary_smoke, 10=county, 
      11=screening_month, 12=pets,   ...   50=income_group, 51=monthly_income_total"

      The script loads 20050 rows.

      Operation directory: /home/myaccount/search-demos/healthcare_demo/logs/LOAD_20190308-194845-563653
       total | failed | rows/s | mb/s | kb/row | p50ms |  p99ms | p999ms | batches
      20,050 |      0 |  2,295 | 0.62 |   0.28 | 83.97 | 274.73 | 333.45 |    1.00
      Operation LOAD_20190308-194845-563653 completed successfully in 8 seconds.
      Last processed positions can be found in positions.txt

   3. Verify the number of records:

      SELECT COUNT(*) FROM healthcare.health_data ;

       count
      -------
       20050
      
      (1 rows)
      
      Warnings :
      Aggregation query used without partition key

3. Create the search index:

   CREATE SEARCH INDEX ON healthcare.health_data 
   WITH COLUMNS * {excluded:false}, age_months, monthly_income_total {excluded: true} ;

   • Only columns identified in the COLUMNS options are included. All columns are included when this option is omitted.
4. Display the schema:

   DESCRIBE ACTIVE SEARCH INDEX SCHEMA ON healthcare.health_data;

   <?xml version="1.0" encoding="UTF-8" standalone="no"?>
   <schema name="autoSolrSchema" version="1.5">
     <types>
       <fieldType class="org.apache.solr.schema.StrField" name="StrField"/>
       <fieldType class="org.apache.solr.schema.TrieIntField" name="TrieIntField"/>
     </types>
     <fields>
       <field indexed="true" multiValued="false" name="grade_completed" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="diagnosed_thyroid_disease" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="pets" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="secondary_smoke" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="diagnosed_lupus" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="gender" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="birthplace" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="income_group" stored="true" type="TrieIntField"/>
       <field indexed="true" multiValued="false" name="marital_status" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="age_months" stored="true" type="TrieIntField"/>
       <field indexed="true" multiValued="false" name="bird" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="hay_fever" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="diagnosed_hay_fever" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="routine_medical_coverage" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="annual_income_20000" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="exam_status" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="other_pet" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="diagnosed_stroke" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="employer_paid_plan" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="family_sequence" stored="true" type="TrieIntField"/>
       <field indexed="true" multiValued="false" name="diagnosed_cataracts" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="major_medical_coverage" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="diagnosed_gout" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="age_unit" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="goiter" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="chronic_bronchitis" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="county" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="num_smokers" stored="true" type="TrieIntField"/>
       <field indexed="true" multiValued="false" name="screening_month" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="diagnosed_emphysema" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="diagnosed_other_cancer" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="id" stored="true" type="TrieIntField"/>
       <field indexed="true" multiValued="false" name="dental_coverage" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="health_status" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="fish" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="dog" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="asthma" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="ethnicity" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="age" stored="true" type="TrieIntField"/>
       <field indexed="true" multiValued="false" name="diagnosed_asthma" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="race_ethnicity" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="diagnosed_congestive_heart_failure" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="family_size" stored="true" type="TrieIntField"/>
       <field indexed="true" multiValued="false" name="race" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="thyroid_disease" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="bronchitis" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="household_size" stored="true" type="TrieIntField"/>
       <field indexed="true" multiValued="false" name="cat" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="diagnosed_goiter" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="diagnosed_skin_cancer" stored="true" type="StrField"/>
       <field indexed="true" multiValued="false" name="fips" stored="true" type="StrField"/>
     </fields>
     <uniqueKey>(id,age)</uniqueKey>
   </schema>