Class: SqlQueryAnalyzer::SequentialScanAdvisor

Inherits:
Object
  • Object
show all
Defined in:
lib/sql_query_analyzer/sequential_scan_advisor.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(query_plan) ⇒ SequentialScanAdvisor

Returns a new instance of SequentialScanAdvisor.



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# File 'lib/sql_query_analyzer/sequential_scan_advisor.rb', line 5

def initialize(query_plan)
  @query_plan = query_plan
end

Instance Attribute Details

#query_plan ⇒ Object (readonly)

Returns the value of attribute query_plan.



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# File 'lib/sql_query_analyzer/sequential_scan_advisor.rb', line 3

def query_plan
  @query_plan
end

Instance Method Details

#enhanced_message ⇒ Object 



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# File 'lib/sql_query_analyzer/sequential_scan_advisor.rb', line 9

def enhanced_message
  table_name, column_names = extract_table_and_columns

  return nil unless sequential_scan_detected?

  if column_names.empty?
    return "👉 [CRITICAL] ⚡ Sequential Scan detected on '#{table_name}', " \
           "but no filter condition found. Likely a full table read " \
           "(e.g., SELECT *), or small table size makes index use unnecessary."
  end

  messages = []
  messages << "👉 [CRITICAL] ⚡ Sequential Scan detected on '#{table_name}', " \
              "and filter involves columns: #{column_names.join(', ')}."
  if missing_composite_index?(table_name, column_names)
    messages << "💡 Consider adding a composite index on: #{column_names.join(', ')}"
  end
  messages.join("\n")
end