**Pattern Template Structure:**

```sql

-- Step 1: CTE for base calculations

WITH pattern_base AS (

SELECT

columns,

WINDOW_FUNCTION() OVER (

PARTITION BY group_columns

ORDER BY sort_columns

[ROWS/RANGE frame_specification]

) as calculated_column

FROM source_table

WHERE filter_conditions

)

-- Step 2: Apply pattern logic

SELECT

columns,

calculated_column,

CASE

WHEN condition THEN 'Result'

ELSE 'Other'

END as pattern_result

FROM pattern_base

WHERE pattern_filter

ORDER BY sort_columns;

```

**Common CTE Patterns:**

```sql

-- Multi-step pattern

WITH step1 AS (...),

step2 AS (...),

final_step AS (...)

SELECT * FROM final_step;

```

**Performance Optimization:**

```sql

-- Always include proper indexes

CREATE INDEX idx_pattern_optimization

ON table(partition_column, order_column);

```