Techniques to make your PySpark applications faster
Proper partitioning is crucial for parallel processing. Repartition your data when needed:
# Repartition to 200 partitions
df = df.repartition(200)
# Partition by a column
df = df.repartition("date")
Cache frequently accessed DataFrames to avoid recomputation:
# Cache a DataFrame in memory
df.cache()
# Persist with storage level
from pyspark.storagelevel import StorageLevel
df.persist(StorageLevel.MEMORY_AND_DISK)
Use broadcast variables for small lookup tables:
lookup_data = {"a": 1, "b": 2, "c": 3}
broadcast_var = sc.broadcast(lookup_data)
# Use in transformations
rdd.map(lambda x: broadcast_var.value.get(x, 0))