I met problem with processing of spark wide dataframe (about 9000 columns and sometimes more).
Task:

1. Create wide DF via groupBy and pivot.
2. Transform columns to vector and processing in to KMeans from pyspark.ml.

So I made extensive frame and try to create vector with VectorAssembler, cached it and trained on it KMeans.
It took about 11 minutes for assembling and 2 minutes for KMeans for 7 different count of clusters on my pc in standalone mode for frame ~500x9000. Another side this processing in pandas (pivot df, and iterate 7 clusters) takes less one minute.
Obviously I understand overhead and performance decreasing for standalone mode and caching and so on but it's really discourages me.
Could somebody explain how I can avoid this overhead?
How peoples work with wide DF instead of using vectorassembler and getting performance decreasing?
More formal question (for sof rules) sound like - How can I speed up this code?

%%time
tmp = (df_states.select('ObjectPath', 'User', 'PropertyFlagValue')
       .groupBy('User')
       .pivot('ObjectPath')
       .agg({'PropertyFlagValue':'max'})
       .fillna(0))
ignore = ['User']
assembler = VectorAssembler(
    inputCols=[x for x in tmp.columns if x not in ignore],
    outputCol='features')
Wall time: 36.7 s

print(tmp.count(), len(tmp.columns))
552, 9378

%%time
transformed = assembler.transform(tmp).select('User', 'features').cache()
Wall time: 10min 45s

%%time
lst_levels = []
for num in range(3, 14):
    kmeans = KMeans(k=num, maxIter=50)
    model = kmeans.fit(transformed)
    lst_levels.append(model.computeCost(transformed))
rs = [i-j for i,j in list(zip(lst_levels, lst_levels[1:]))]
for i, j in zip(rs, rs[1:]):
    if i - j < j:
        print(rs.index(i))
        kmeans = KMeans(k=rs.index(i) + 3, maxIter=50)
        model = kmeans.fit(transformed)
        break
 Wall time: 1min 32s

Config:

.config("spark.sql.pivotMaxValues", "100000") \
.config("spark.sql.autoBroadcastJoinThreshold", "-1") \
.config("spark.sql.shuffle.partitions", "4") \
.config("spark.sql.inMemoryColumnarStorage.batchSize", "1000") \