. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 1.11 Performance Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 1.12 Transactions == join_query.c.id # Becomes: (t1."parent_id" = "jq"."id") 1.11 Performance Techniques This section outlines some techniques for improving performance when using peewee. 1.11.1 Avoiding N+1 queries The optimizations employed by the database when joining or executing a subquery. 1.11. Performance Techniques 105 peewee Documentation, Release 3.3.0 Peewee provides several APIs for mitigating N+1 query

Keys Traversing foreign keys Joining tables Implementing Many to Many Self-joins Performance Techniques Avoiding N+1 queries Iterating over lots of rows Speeding up Bulk Inserts Transactions Context parent == join_query.c.id # Becomes: (t1."parent_id" = "jq"."id") Performance Techniques This section outlines some techniques for improving performance when using peewee. Avoiding N+1 queries The term Filename to read. Contents of the file. HELPER gzip(data[, compression=9]) data (bytes) – Data to compress. compression (int) – Compression level (9 is max). Compressed binary data. gunzip(data) Parameters:

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 1.11 Performance Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 1.12 Transactions web frameworks, see the Adding Request Hooks section. Note: For advanced connection management techniques, see the advanced connection management section. To use this database with your models, set the == join_query.c.id # Becomes: (t1."parent_id" = "jq"."id") 1.11 Performance Techniques This section outlines some techniques for improving performance when using peewee. 1.11.1 Avoiding N+1 queries The

namedtuples Returning Clause Foreign Keys and Joins Implementing Many to Many Self-joins Performance Techniques Query operators Three valued logic Adding user-defined operators Expressions SQL Functions SQL parent == join_query.c.id # Becomes: (t1."parent_id" = "jq"."id") Performance Techniques This section outlines some techniques for improving performance when using peewee. Avoiding N+1 queries The term Filename to read. Contents of the file. HELPER gzip(data[, compression=9]) data (bytes) – Data to compress. compression (int) – Compression level (9 is max). Compressed binary data. gunzip(data) Parameters:

Keys Traversing foreign keys Joining tables Implementing Many to Many Self-joins Performance Techniques Avoiding N+1 queries Iterating over lots of rows Speeding up Bulk Inserts Transactions Context parent == join_query.c.id # Becomes: (t1."parent_id" = "jq"."id") Performance Techniques This section outlines some techniques for improving performance when using peewee. Avoiding N+1 queries The term Filename to read. Contents of the file. HELPER gzip(data[, compression=9]) data (bytes) – Data to compress. compression (int) – Compression level (9 is max). Compressed binary data. gunzip(data) Parameters:

Keys Traversing foreign keys Joining tables Implementing Many to Many Self-joins Performance Techniques Avoiding N+1 queries Iterating over lots of rows Speeding up Bulk Inserts Transactions Context parent == join_query.c.id # Becomes: (t1."parent_id" = "jq"."id") Performance Techniques This section outlines some techniques for improving performance when using peewee. Avoiding N+1 queries The term Filename to read. Contents of the file. HELPER gzip(data[, compression=9]) data (bytes) – Data to compress. compression (int) – Compression level (9 is max). Compressed binary data. gunzip(data) Parameters:

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 1.11 Performance Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 1.12 Transactions == join_query.c.id # Becomes: (t1."parent_id" = "jq"."id") 1.11 Performance Techniques This section outlines some techniques for improving performance when using peewee. 106 Chapter 1. Contents: peewee method is usually faster but will involve a query for each table being selected. 1.11. Performance Techniques 107 peewee Documentation, Release 3.4.0 Using prefetch peewee supports pre-fetching related

Keys Traversing foreign keys Joining tables Implementing Many to Many Self-joins Performance Techniques Avoiding N+1 queries Iterating over lots of rows Speeding up Bulk Inserts Transactions Context web frameworks, see the Adding Request Hooks section. Note For advanced connection management techniques, see the advanced connection management section. To use this database with your models, set the parent == join_query.c.id # Becomes: (t1."parent_id" = "jq"."id") Performance Techniques This section outlines some techniques for improving performance when using peewee. Avoiding N+1 queries The term

join_query.c.id # Becomes: (t1."parent_id" = "jq"."id") 1.7.22 Performance Techniques This section outlines some techniques for improving performance when using peewee. 1.7. Querying 81 peewee Documentation Returns Contents of the file. HELPER gzip(data[, compression=9]) Parameters • data (bytes) – Data to compress. • compression (int) – Compression level (9 is max). Returns Compressed binary data. found in the playhouse.fields module. class CompressedField([compression_level=6[, algorithm=’zlib’[, **kwargs]]]) Parameters • compression_level (int) – A value from 0 to 9. • algorithm (str) – Either

Filename to read. Contents of the file. HELPER gzip(data[, compression=9]) data (bytes) – Data to compress. compression (int) – Compression level (9 is max). Returns: Parameters: Returns: Parameters: can be found in the playhouse.fields module. class CompressedField([compression_level=6[, algorithm='zlib'[, **kwargs]]]) compression_level (int) – A value from 0 to 9. algorithm (str) – Either 'zlib' group. For a thorough discuss of various techniques, check out my blog post Querying the top item by group with Peewee ORM [http://charlesleifer.com/blog/techniques-for-querying-lists-of- objects-and-de