Add support for "uuid" type in tracking_column_type

docs/input-jdbc.asciidoc

@@ -127,7 +127,7 @@ Here is the list:
 
 |==========================================================
 |sql_last_value | The value used to calculate which rows to query. Before any query is run,
-this is set to Thursday, 1 January 1970, or 0 if `use_column_value` is true and
+this is set to Thursday, 1 January 1970, 0, or 00000000-0000-0000-0000-000000000000 if `use_column_value` is true and
 `tracking_column` is set. It is updated accordingly after subsequent queries are run.
 |offset, size| Values used with manual paging mode to explicitly implement the paging.
 Supported only if <<plugins-{type}s-{plugin}-jdbc_paging_enabled>> is enabled and
@@ -240,7 +240,7 @@ This plugin supports the following configuration options plus the <<plugins-{typ
 | <<plugins-{type}s-{plugin}-statement_filepath>> |a valid filesystem path|No
 | <<plugins-{type}s-{plugin}-target>> | {logstash-ref}/field-references-deepdive.html[field reference] | No
 | <<plugins-{type}s-{plugin}-tracking_column>> |<<string,string>>|No
-| <<plugins-{type}s-{plugin}-tracking_column_type>> |<<string,string>>, one of `["numeric", "timestamp"]`|No
+| <<plugins-{type}s-{plugin}-tracking_column_type>> |<<string,string>>, one of `["numeric", "timestamp", "uuid"]`|No
 | <<plugins-{type}s-{plugin}-use_column_value>> |<<boolean,boolean>>|No
 | <<plugins-{type}s-{plugin}-use_prepared_statements>> |<<boolean,boolean>>|No
 |=======================================================================
@@ -645,10 +645,24 @@ The column whose value is to be tracked if `use_column_value` is set to `true`
 [id="plugins-{type}s-{plugin}-tracking_column_type"]
 ===== `tracking_column_type`
 
-  * Value can be any of: `numeric`, `timestamp`
+  * Value can be any of: `numeric`, `timestamp`, `uuid`
   * Default value is `"numeric"`
 
-Type of tracking column. Currently only "numeric" and "timestamp"
+Type of tracking column. Currently only "numeric", "timestamp" and "uuid"
+
+NOTE: Example of uuid type usage in PostgreSQL.
+[source,ruby]
+---------------------------------------------------------------------------------------------------
+input {
+  jdbc {
+    statement => "SELECT id, mycolumn1, mycolumn2 FROM my_table WHERE id > :sql_last_value::uuid"
+    use_column_value => true
+    tracking_column => "id"
+    tracking_column_type => "uuid"
+    # ... other configuration bits
+  }
+}
+---------------------------------------------------------------------------------------------------
 
 [id="plugins-{type}s-{plugin}-use_column_value"]
 ===== `use_column_value`

lib/logstash/inputs/jdbc.rb

@@ -191,8 +191,8 @@ module LogStash module Inputs class Jdbc < LogStash::Inputs::Base
   # If tracking column value rather than timestamp, the column whose value is to be tracked
   config :tracking_column, :validate => :string
 
-  # Type of tracking column. Currently only "numeric" and "timestamp"
-  config :tracking_column_type, :validate => ['numeric', 'timestamp'], :default => 'numeric'
+  # Type of tracking column. Currently only "numeric", "timestamp" and "uuid"
+  config :tracking_column_type, :validate => ['numeric', 'timestamp', 'uuid'], :default => 'numeric'
 
   # Whether the previous run state should be preserved
   config :clean_run, :validate => :boolean, :default => false

lib/logstash/plugin_mixins/jdbc/value_tracking.rb

@@ -12,9 +12,15 @@ def self.build_last_value_tracker(plugin)
         handler.clean
       end
 
-      if plugin.use_column_value && plugin.tracking_column_type == "numeric"
-        # use this irrespective of the jdbc_default_timezone setting
-        NumericValueTracker.new(handler)
+      tracking_column_types = ['numeric', 'uuid']
+      if plugin.use_column_value && tracking_column_types.include?(plugin.tracking_column_type)
+        case plugin.tracking_column_type
+        when "numeric"
+          # use this irrespective of the jdbc_default_timezone setting
+          NumericValueTracker.new(handler)
+        when "uuid"
+          UuidValueTracker.new(handler)
+        end
       else
         if plugin.jdbc_default_timezone.nil?
           # no TZ stuff for Sequel, use Time
@@ -34,7 +40,7 @@ def initialize(handler)
     end
 
     if Psych::VERSION&.split('.')&.first.to_i >= 4
-      YAML_PERMITTED_CLASSES = [::DateTime, ::Time, ::BigDecimal].freeze
+      YAML_PERMITTED_CLASSES = [::DateTime, ::Time, ::BigDecimal, ::String].freeze
       def self.load_yaml(source)
         Psych::safe_load(source, permitted_classes: YAML_PERMITTED_CLASSES)
       end
@@ -81,6 +87,17 @@ def set_value(value)
     end
   end
 
+  class UuidValueTracker < ValueTracking
+    def set_initial
+      common_set_initial(:uuid, "00000000-0000-0000-0000-000000000000")
+    end
+
+    def set_value(value)
+      return unless value.is_a?(String)
+      @value = value
+    end
+  end
+
   class DateTimeValueTracker < ValueTracking
     def set_initial
       common_set_initial(:to_datetime, DateTime.new(1970))

spec/inputs/jdbc_spec.rb

@@ -35,11 +35,12 @@
       db.create_table :test_table do
         DateTime     :created_at
         BigDecimal   :big_num
+        String       :uuid
         Integer      :num
         String       :string
         DateTime     :custom_time
       end
-      db << "CREATE TABLE types_table (num INTEGER, string VARCHAR(255), started_at DATE, custom_time TIMESTAMP, ranking DECIMAL(16,6))"
+      db << "CREATE TABLE types_table (num INTEGER, string VARCHAR(255), started_at DATE, custom_time TIMESTAMP, ranking DECIMAL(16,6), uuid VARCHAR(36))"
       db << "CREATE TABLE test1_table (num INTEGER, string VARCHAR(255), custom_time TIMESTAMP, created_at TIMESTAMP)"
     end
   end
@@ -1522,7 +1523,7 @@
     end
 
     before do
-      db << "INSERT INTO types_table (num, string, started_at, custom_time, ranking) VALUES (1, 'A test', '1999-12-31', '1999-12-31 23:59:59', 95.67)"
+      db << "INSERT INTO types_table (num, string, started_at, custom_time, ranking, uuid) VALUES (1, 'A test', '1999-12-31', '1999-12-31 23:59:59', 95.67, '018f15f3-6cfd-7a1b-b70f-d97ed8a73128')"
 
       plugin.register
     end
@@ -1539,6 +1540,7 @@
       expect(event.get("started_at")).to be_a_logstash_timestamp_equivalent_to("1999-12-31T00:00:00.000Z")
       expect(event.get("custom_time")).to be_a_logstash_timestamp_equivalent_to("1999-12-31T23:59:59.000Z")
       expect(event.get("ranking").to_f).to eq(95.67)
+      expect(event.get("uuid")).to eq("018f15f3-6cfd-7a1b-b70f-d97ed8a73128")
     end
   end
 
@@ -1552,7 +1554,7 @@
     end
 
     before(:each) do
-      db << "INSERT INTO types_table (num, string, started_at, custom_time, ranking) VALUES (1, 'A test', '1999-12-31', '2021-11-07 01:23:45', 95.67)"
+      db << "INSERT INTO types_table (num, string, started_at, custom_time, ranking, uuid) VALUES (1, 'A test', '1999-12-31', '2021-11-07 01:23:45', 95.67, '018f15f3-6cfd-7a1b-b70f-d97ed8a73128')"
       plugin.register
     end