SELECT count(*) AS `count` FROM (SELECT * FROM ip_bundle_data_20190813) AS `t1` LIMIT 1

logstash-7.2.0\vendor\bundle\jruby\2.5.0\gems\logstash-input-jdbc-4.3.13\lib\logstash\plugin_mixins\jdbc\jdbc.rb

// line:100 => config
# 开启子查询分页 @boole 2018-03-30
config :subquery_paging_enabled, :validate => :boolean, :default => false
# 总数sql，结果集列名为sum。for example `select count(*) as sum from goods` @boole 2018-03-30
config :sum_statement, :validate => :string

// line:254 => perform_query
private
    def perform_query(query)
		#subquery paging @boole 2018-03-30
		if @subquery_paging_enabled
		  @logger.info("################### subquery paging optimization ################")
		  data_sum = @database[@sum_statement].get(:sum)
		  @logger.info("data_sum=#{data_sum}")
		  data_offset = 0
			while data_offset < data_sum do
				@logger.info("data_offset=#{data_offset}")
				sub_page_query = @database[@statement, symbolized_params({"data_offset" => data_offset, "jdbc_page_size" => @jdbc_page_size})]
				sub_page_query.each do |row|
				yield row
			end
			data_offset += @jdbc_page_size
		end
		elsif @jdbc_paging_enabled
        query.each_page(@jdbc_page_size) do |paged_dataset|
          paged_dataset.each do |row|
            yield row
          end
        end
      else
        query.each do |row|
          yield row
        end
      end
    end

statement => "SELECT * FROM ip_bundle_data_20190813 limit :data_offset,:jdbc_page_size"

subquery_paging_enabled => "true"

sum_statement => "select count(*) as `count` from ip_bundle_data_20190813"