Class: SqlQueryAnalyzer::SequentialScanAdvisor

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

Instance Method Summary collapse

Constructor Details

#initialize(line_text) ⇒ SequentialScanAdvisor

Returns a new instance of SequentialScanAdvisor.



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

def initialize(line_text)
  @line_text = line_text
end

Instance Method Details

#enhanced_message ⇒ Object 



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# File 'lib/sql_query_analyzer/sequential_scan_advisor.rb', line 7

def enhanced_message
  table_name, column_names = extract_table_and_columns
  return nil unless table_name

  if column_names.empty?
    return "⚡ 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

  missing_indexes = column_names.select do |column|
    !index_exists?(table_name, column)
  end

  if missing_indexes.any?
    "⚡ Sequential Scan detected on '#{table_name}'. Consider adding indexes on: #{missing_indexes.join(', ')}."
  else
    "⚡ Sequential Scan detected on '#{table_name}', but indexes seem to exist. Might be due to low table size or outdated stats."
  end
end